AK reraised preflop. 5/10

[Heimdal]

6-handed 5/10 on Party.

Effective stacks $913. UTG limps, 1 fold. Hero raises to $40 in CO with red AK. Unknown button (me) who just sat down, makes it $125 to go. Folded back to hero who calls. Flop is K [img]/images/graemlins/spade.gif[/img]J [img]/images/graemlins/spade.gif[/img]3[img]/images/graemlins/spade.gif[/img].
There is $275 in the pot and hero has $788 left. What is the best line here against an unknown?

Hero chose to pot it and called a push from button. Good?

Thanks