There was a blog post and discussion here about this a few months ago: https://news.ycombinator.com/item?id=34676186

A $5 instance gets you something like 1 core on a slightly dated CPU. Aka approximately as much processing power as a top of the line desktop processor 15 years ago. Aka enough processing power to fill a 25 Gb/s port with TLS data (not that you have the port to go with that).

A few requests per millisecond should be well within the capabilities of this instance, depending on the complexity of each request of course.