Bet that flop, don't consider it a donk bet if you hit the flop.
a donk bet by definition, although named after being bad, is any bet made while a player in a later position has the betting initiative. so yes, this is a donk bet...
whether or not its good, i would prefer it if there was more that the other player can call you with, otherwise he's going to fold a high percentage of the time. if the board was something like KhQh8x it would be better because then villain will have a lot of Kx Qx and straight draw type of hands that can call your bet.
on this board though, youre more likely to get paid by checking and villain will be more likely to cbet (even though its not a good board for him to cbet, most players make the mistake of cbetting too often on boards like this)
so i would prefer a check-call here. if a high non-heart card comes on turn or river, a check raise on the turn, or leading out with a bet on the river will probably be good, just of course be careful if a heart comes. probably better to call one street and maybe check/fold to a river bet in the case of a heart on the turn, and check/call the river if the turn is a non-heart and the river is a heart...
also, im assuming stacks here are somewhat deep? 40bb+?
that would be good information to have if stacks are shallower than 40bb then that changes the whole play