Call or fold? Is this a close decision?

[EnderW27]

Personally I think it is. It's a hand I played sometime last week that I've been thinking about.

MP1 open raises in a limit game. MP3 cold calls and it's folded to you in the BB with ATo. You call.

Flop is KsJ3s matching your A.

You check. MP1 checks. MP3 bets. What do you do?
Do the stakes matter? Does your read on your opponents matter? Or is this a pure math problem? Is this even close?