KK - standard flop against short stack

[Isura]

Villain bought in for $60, 1/2 blinds. I have K[img]/images/graemlins/diamond.gif[/img] K[img]/images/graemlins/spade.gif[/img] in MP.

Preflop: villain raises to $4, I reraise to $15, 4 folds, villain calls.

Flop ($33): A[img]/images/graemlins/diamond.gif[/img] A[img]/images/graemlins/heart.gif[/img] 7[img]/images/graemlins/club.gif[/img]
Villain checks, I ?

He was $45 left. Push or let him catch a pair on the turn? This situation comes up a lot at the site I play at (so many short stacks).