How to obtain KCV from the key
To calculate the KCV for AES, you take the first three bytes of the encryption of zero under your key.

Indeed, the case you've given is precisely this - the zero vector encrypted under the key 48C3B4286FF421A4A328E68AD9E542A4 is 77dc841daeb43315fed9acdf2f965f45, which restricts to 77dc84.

In your question you say you already have AES-128 encryption, at which point calculating the KCV shouldn't be a problem. I won't ask why you're calculating a KCV, but be warned that there may well be better ways to achieve your actual goal. The other article with this tag provides a reasonable discussion about the benefits of them.