Fold pf. Are people serious. He is on the button against bad players 300bb deep. I'd probably raise it up if 1 of my cards was the joker.
As for the hand itself, toughish without reads. I'd try to be answering whether he can do this with A2, A8, 98, 9x with a fd and a bluff and from that figure out where to go.
I think your line is fine against an unknown though.