Uh, yes, very impressive. I was limited to a single spindle of 7200rpm HDD on our Mining pool and I couldn't get my SQL db response below 10ms even with everything supposedly cached in RAM. I realize that was a really crappy hardware setup for a SQL server, but are you using SSD?
Edit: I work with and have tuned the shit out of a 24 spindle NetApp system at work, so I'm not new to DB and disk performance measuring.
I'm using Rackspace Cloud. The private networks, I/O and CPU are the awesome parts. Actually I'm handling this amount of traffic with 2 web servers utilizing 500 MB RAM each, and MySQL database is only utilizing 120 MB RAM. (Redis is negligible.)
So I think it really has to do with the actual code quality and optimization. Hardware is important too, but throwing money at servers is always easy.
I'm a n00b in scaling by the way.