Am I overplaying KK?

[Toonces]

3/5 NL at Potawatomi. Hero is UTG+1. Button is one of the better players at the table, but I've only been at the table for 45 minutes. MP1 is mostly loose-passive asian guy. Hero and button both have about $900 stacks.

Hero raises on KK to $25. MP1 calls. Button re-raises to $75. Hero re-raises to $200. MP1 folds. Button calls.

Flop is T T 6 rainbow. Hero bets $300.

Thoughts?