Raise more pre, pot sized. $0.35 or $0.40.

Put him on a river range and figure out if it's +EV to call.

Seriously if he really had a set or AK he'd have to be a complete dumb to bet the river like this when every conceivable draw has completed. Any A has a straight and there is 3 to a flush on the board. He'd also have raised a set earlier than that imo.

You could argue for a blocking bet on the river I suppose, if you're worried to get bluffed.