Hi!
It must have been a temporary server outage, I just tried to create a new index and everything went fine: http://i.imgur.com/Xdot1NR.png
I have changed the engine to Index Table, the performance tracker shows 0.1 – 0.2 seconds for the execution runtime, which is pretty neat now. The actual response time is of course different, because WordPress initializes everything within an ajax request for safety and compatibility reasons. This loading time depends on number and quality of the plugins used (and the theme as well).