hold 'em or fold 'em

Don't remember exact stack amounts, but here goes. Six handed NL Hold Em:
-- Action folds around to the button.
-- Button raises around 4X BB.
-- I'm in the SB w/ AQs. I call.
-- SB folds
FLOP: 2,K,K
I check.
Button raises 3/4 the pot.
I call.
TURN: K
I check.
Button goes all in. (about 3/4 of my stack)
I gotta lay that down, right? I feel he's respresented a pocket pair and now I'm not looking so good. Thoughts?