diff --git a/moto/ec2/models/key_pairs.py b/moto/ec2/models/key_pairs.py
--- a/moto/ec2/models/key_pairs.py
+++ b/moto/ec2/models/key_pairs.py
@@ -1,8 +1,7 @@
-from typing import Any, Dict, List
+from typing import Any, Dict, List, Optional
 
-from moto.core import BaseModel
+from .core import TaggedEC2Resource
 from ..exceptions import (
-    FilterNotImplementedError,
     InvalidKeyPairNameError,
     InvalidKeyPairDuplicateError,
     InvalidKeyPairFormatError,
@@ -18,38 +17,55 @@
 from moto.core.utils import iso_8601_datetime_with_milliseconds, utcnow
 
 
-class KeyPair(BaseModel):
-    def __init__(self, name: str, fingerprint: str, material: str):
+class KeyPair(TaggedEC2Resource):
+    def __init__(
+        self,
+        name: str,
+        fingerprint: str,
+        material: str,
+        tags: Dict[str, str],
+        ec2_backend: Any,
+    ):
         self.id = random_key_pair_id()
         self.name = name
         self.fingerprint = fingerprint
         self.material = material
         self.create_time = utcnow()
+        self.ec2_backend = ec2_backend
+        self.add_tags(tags or {})
 
     @property
     def created_iso_8601(self) -> str:
         return iso_8601_datetime_with_milliseconds(self.create_time)
 
-    def get_filter_value(self, filter_name: str) -> str:
+    def get_filter_value(
+        self, filter_name: str, method_name: Optional[str] = None
+    ) -> str:
         if filter_name == "key-name":
             return self.name
         elif filter_name == "fingerprint":
             return self.fingerprint
         else:
-            raise FilterNotImplementedError(filter_name, "DescribeKeyPairs")
+            return super().get_filter_value(filter_name, "DescribeKeyPairs")
 
 
 class KeyPairBackend:
     def __init__(self) -> None:
         self.keypairs: Dict[str, KeyPair] = {}
 
-    def create_key_pair(self, name: str, key_type: str = "rsa") -> KeyPair:
+    def create_key_pair(
+        self, name: str, key_type: str, tags: Dict[str, str]
+    ) -> KeyPair:
         if name in self.keypairs:
             raise InvalidKeyPairDuplicateError(name)
         if key_type == "ed25519":
-            keypair = KeyPair(name, **random_ed25519_key_pair())
+            keypair = KeyPair(
+                name, **random_ed25519_key_pair(), tags=tags, ec2_backend=self
+            )
         else:
-            keypair = KeyPair(name, **random_rsa_key_pair())
+            keypair = KeyPair(
+                name, **random_rsa_key_pair(), tags=tags, ec2_backend=self
+            )
 
         self.keypairs[name] = keypair
         return keypair
@@ -77,7 +93,9 @@ def describe_key_pairs(
         else:
             return results
 
-    def import_key_pair(self, key_name: str, public_key_material: str) -> KeyPair:
+    def import_key_pair(
+        self, key_name: str, public_key_material: str, tags: Dict[str, str]
+    ) -> KeyPair:
         if key_name in self.keypairs:
             raise InvalidKeyPairDuplicateError(key_name)
 
@@ -88,7 +106,11 @@ def import_key_pair(self, key_name: str, public_key_material: str) -> KeyPair:
 
         fingerprint = public_key_fingerprint(public_key)
         keypair = KeyPair(
-            key_name, material=public_key_material, fingerprint=fingerprint
+            key_name,
+            material=public_key_material,
+            fingerprint=fingerprint,
+            tags=tags,
+            ec2_backend=self,
         )
         self.keypairs[key_name] = keypair
         return keypair
diff --git a/moto/ec2/responses/key_pairs.py b/moto/ec2/responses/key_pairs.py
--- a/moto/ec2/responses/key_pairs.py
+++ b/moto/ec2/responses/key_pairs.py
@@ -5,8 +5,9 @@ class KeyPairs(EC2BaseResponse):
     def create_key_pair(self) -> str:
         name = self._get_param("KeyName")
         key_type = self._get_param("KeyType")
+        tags = self._parse_tag_specification("key-pair").get("key-pair", {})
         self.error_on_dryrun()
-        keypair = self.ec2_backend.create_key_pair(name, key_type)
+        keypair = self.ec2_backend.create_key_pair(name, key_type, tags=tags)
         return self.response_template(CREATE_KEY_PAIR_RESPONSE).render(keypair=keypair)
 
     def delete_key_pair(self) -> str:
@@ -26,9 +27,10 @@ def describe_key_pairs(self) -> str:
     def import_key_pair(self) -> str:
         name = self._get_param("KeyName")
         material = self._get_param("PublicKeyMaterial")
+        tags = self._parse_tag_specification("key-pair").get("key-pair", {})
         self.error_on_dryrun()
 
-        keypair = self.ec2_backend.import_key_pair(name, material)
+        keypair = self.ec2_backend.import_key_pair(name, material, tags=tags)
         return self.response_template(IMPORT_KEYPAIR_RESPONSE).render(keypair=keypair)
 
 
@@ -41,6 +43,16 @@ def import_key_pair(self) -> str:
            <keyPairId>{{ keypair.id }}</keyPairId>
            <keyName>{{ keypair.name }}</keyName>
            <keyFingerprint>{{ keypair.fingerprint }}</keyFingerprint>
+           {% if keypair.get_tags() %}
+             <tagSet>
+               {% for tag in keypair.get_tags() %}
+                 <item>
+                   <key>{{ tag.key }}</key>
+                   <value>{{ tag.value }}</value>
+                 </item>
+               {% endfor %}
+             </tagSet>
+           {% endif %}
       </item>
     {% endfor %}
     </keySet>
@@ -52,6 +64,16 @@ def import_key_pair(self) -> str:
    <keyName>{{ keypair.name }}</keyName>
    <keyFingerprint>{{ keypair.fingerprint }}</keyFingerprint>
    <keyMaterial>{{ keypair.material }}</keyMaterial>
+   {% if keypair.get_tags() %}
+   <tagSet>
+     {% for tag in keypair.get_tags() %}
+       <item>
+         <key>{{ tag.key }}</key>
+         <value>{{ tag.value }}</value>
+       </item>
+     {% endfor %}
+   </tagSet>
+   {% endif %}
 </CreateKeyPairResponse>"""
 
 
@@ -66,4 +88,14 @@ def import_key_pair(self) -> str:
     <keyPairId>{{ keypair.id }}</keyPairId>
     <keyName>{{ keypair.name }}</keyName>
     <keyFingerprint>{{ keypair.fingerprint }}</keyFingerprint>
+    {% if keypair.get_tags() %}
+   <tagSet>
+     {% for tag in keypair.get_tags() %}
+       <item>
+         <key>{{ tag.key }}</key>
+         <value>{{ tag.value }}</value>
+       </item>
+     {% endfor %}
+   </tagSet>
+   {% endif %}
   </ImportKeyPairResponse>"""

Hi @inventvenkat, that filter isn't supported by AWS either, as far as I can tell? 

https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/ec2/client/describe_key_pairs.html only lists `key-pair-id`, `fingerprint`, `key-name`, `tag-key` and `tag`.

Edit: We have internal tests for the `fingerprint` and `key-name` filters, so those are already supported.
> Hi @inventvenkat, that filter isn't supported by AWS either, as far as I can tell?
> 
> https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/ec2/client/describe_key_pairs.html only lists `key-pair-id`, `fingerprint`, `key-name`, `tag-key` and `tag`.
> 
> Edit: We have internal tests for the `fingerprint` and `key-name` filters, so those are already supported.

Hi @bblommers , i missed writing tag while creating the issue. edited it now
diff --git a/tests/test_ec2/test_key_pairs.py b/tests/test_ec2/test_key_pairs.py
--- a/tests/test_ec2/test_key_pairs.py
+++ b/tests/test_ec2/test_key_pairs.py
@@ -254,3 +254,51 @@ def test_key_pair_filters_boto3():
         Filters=[{"Name": "fingerprint", "Values": [kp3.key_fingerprint]}]
     )["KeyPairs"]
     assert set([kp["KeyName"] for kp in kp_by_name]) == set([kp3.name])
+
+
+@mock_ec2
+def test_key_pair_with_tags():
+    client = boto3.client("ec2", "us-east-1")
+
+    key_name_1 = str(uuid4())[0:6]
+    key_name_2 = str(uuid4())[0:6]
+    key_name_3 = str(uuid4())[0:6]
+    key_name_4 = str(uuid4())[0:6]
+    resp = client.create_key_pair(
+        KeyName=key_name_1,
+        TagSpecifications=[
+            {"ResourceType": "key-pair", "Tags": [{"Key": "key", "Value": "val1"}]}
+        ],
+    )
+    assert resp["Tags"] == [{"Key": "key", "Value": "val1"}]
+    kp1 = resp["KeyPairId"]
+
+    kp2 = client.create_key_pair(
+        KeyName=key_name_2,
+        TagSpecifications=[
+            {"ResourceType": "key-pair", "Tags": [{"Key": "key", "Value": "val2"}]}
+        ],
+    )["KeyPairId"]
+
+    assert "Tags" not in client.create_key_pair(KeyName=key_name_3)
+
+    key_pairs = client.describe_key_pairs(
+        Filters=[{"Name": "tag-key", "Values": ["key"]}]
+    )["KeyPairs"]
+    assert [kp["KeyPairId"] for kp in key_pairs] == [kp1, kp2]
+
+    key_pairs = client.describe_key_pairs(
+        Filters=[{"Name": "tag:key", "Values": ["val1"]}]
+    )["KeyPairs"]
+    assert len(key_pairs) == 1
+    assert key_pairs[0]["KeyPairId"] == kp1
+    assert key_pairs[0]["Tags"] == [{"Key": "key", "Value": "val1"}]
+
+    resp = client.import_key_pair(
+        KeyName=key_name_4,
+        PublicKeyMaterial=RSA_PUBLIC_KEY_OPENSSH,
+        TagSpecifications=[
+            {"ResourceType": "key-pair", "Tags": [{"Key": "key", "Value": "val4"}]}
+        ],
+    )
+    assert resp["Tags"] == [{"Key": "key", "Value": "val4"}]

add support to ec2 describe-key-pairs with filters
### Overview
Implement support for describe_key_pairs with filter option.

### Steps to reproduce
```shell
awslocal ec2 describe-key-pairs --region us-east-2 --filters "Name=tag:ManagedBy,Values=hyperswitch"
```
following is the error
```shell
An error occurred (InternalFailure) when calling the DescribeKeyPairs operation: The filter 'tag:ManagedBy' for DescribeKeyPairs has not been implemented in Moto yet. Feel free to open an issue at https://github.com/getmoto/moto/issues
``` 

tests/test_ec2/test_key_pairs.py::test_key_pair_with_tags
tests/test_ec2/test_key_pairs.py::test_key_pairs_import_exist_boto3 tests/test_ec2/test_key_pairs.py::test_key_pairs_import_boto3[rsa-openssh] tests/test_ec2/test_key_pairs.py::test_key_pairs_delete_exist_boto3 tests/test_ec2/test_key_pairs.py::test_key_pairs_invalid_id_boto3 tests/test_ec2/test_key_pairs.py::test_key_pairs_create_boto3[ed25519] tests/test_ec2/test_key_pairs.py::test_key_pairs_create_boto3[rsa] tests/test_ec2/test_key_pairs.py::test_key_pairs_invalid_boto3 tests/test_ec2/test_key_pairs.py::test_key_pairs_create_dryrun_boto3 tests/test_ec2/test_key_pairs.py::test_key_pairs_create_exist_boto3 tests/test_ec2/test_key_pairs.py::test_key_pairs_delete_no_exist_boto3 tests/test_ec2/test_key_pairs.py::test_key_pairs_import_boto3[rsa-rfc4716] tests/test_ec2/test_key_pairs.py::test_key_pairs_empty_boto3 tests/test_ec2/test_key_pairs.py::test_key_pairs_import_boto3[ed25519] tests/test_ec2/test_key_pairs.py::test_key_pair_filters_boto3