3/6 live game facing wild play in the BB, your 4 bet requirements?

[SumZero]

At a very live 3/6 table at Artichoke Joe's. I'm in the BB. UTG (who is one of the better players on the table) posts a live 6. Folded to button (who is a LAG and one of the worst players at the table) who 3 bets it without looking at his hand. SB folds. With what range of hands do you 4-bet here from the BB?

Actual hand results:
I had KQo and made it 4 bets. I got 2 callers and flopped the AJT straight and brought UTG along for a bet at each round.

A couple of the players not in the hand thought the 4-bet with KQo was terrible and that I was very lucky. I thought, in this situation, that the 4-bet would be standard play.