Any particular reads on opponents other then they are old ?
It is a bad board for you sure, but I see no reason not to c-bet, when you decide to raise 4x from UTG it says a lot about the range, meaning A is a huge part of it, as well as QQ, KK. If you do have pocket pair, it is very likely you have one with a heart, therefore it is easy to represent a hand. In case you get re-raised, which is a possibility, then fold.
Also, on such a board, c-betting would seem really strong, especially in a live game. But once the action is checked around, you pretty much allow first to act on the turn to bet it with any two cards that have one heart like JT, QJ, KJ, KT, QT...
I know that the size (20$) would mean you would invest total of 30% of your stack, but KK is worth it. More so, when that A hits the turn, it becomes less likely opponent has one.
If you are that afraid of all the hands opponent can have, I think you would end up folding way too many of your hands.
To sum it up: c-bet the flop, but the way you played it turn is a 50-50 decision.
Personally would opt for a call, considering that villain is mostly semi-bluffing there rather then value betting.