Database design for ~ 2.7B rows per year / 26.000 data points every five minutes
I work for an IoT company and have recently implemented something similar (device sensor data readings) using a Kinesis stream, Spot Instances and DynamoDB.

The Spot Instances were a cost saving step to replace the Lambdas, which were processing the stream data and bulk inserting to DynamoDB, they were costing too much.  We changed the Lambdas to EC2s and then to Spots to save cash.

I would suggest trying the Lambdas to get data from SQS and put it in a DB, but for scale and cheapness please look at DynamoDB for storage. The downside of DynamoDB is that you have to know your query paths before you build the table but as you are using an API you will probably know what those are.