FTP $60K guaranteed, level 3 - TPTK vs 2 - turn push?

[The Student]

Don't have the HH, but here it is:

UTG+2 (3300)
Hero = UTG+3 (2940)
CO (4500)

blinds are 20/40
UTG+2 limps.
(So far he has showndown once, when he PFRed in LP with A/Qo, got called by the btn and the BB. Flop was A/4/4 with 2 diamonds, BB bet, he raised, and got called by both players. Turn was a 6 [img]/images/graemlins/spade.gif[/img], he bet again, and got called twice again. River K was checked around and he split the pot with BB's weak ace.)
I pot it to 180 with A/Ks and get called by CO and UTG+2.

Flop comes A/8/5 rainbow with 600 in the pot.
I bet 450 and get called by both players.

Turn is 4 putting two spades up and pot is now at 1950. I have 2200 or so left and its checked to me. I want to take down this pot now, but there is no draw I can put them on with that rainbow flop. So either I'm way ahead, behind to two pair, or way behind to a set. I have seen the UTG+2 play A/Q aggressively vs two players on a paired - do I press my TPTK here? Could both UTG+2 and the CO have called me on the flop with weaker aces? Or do I slow down in case one of them has a set?

Anyone push here? Anyone check or check-call here, hoping to call or check-call down a river bet?

thanks,

ts-