It makes a huge difference whether or not you raised pre-flop. I rarely let TPTK go with AK if I raised pre-flop. Sure, they could have the set...but more often than not they have top pair with a worse kicker. There's exceptions to every rule....flop comes with 3 face cards and I only have 1 pair...flop comes 3 of a suit that I don't hold (and there's heavy action)...but as a general rule I treat a pair of aces/kings when I hold AK in a raised pot as a pretty strong hand. You'll run into trips at times, as well as AA when you've hit your K. You can't let that stop you from playing AK strongly when you raised pre-flop and it hits. In an unraised pot, espcially a multiway, 1-pair is just not as strong and you have to consider folding it when there's heavy heat.

Post some hand histories where you've hit AK. The texture of the flop and the pre-flop action does matter a lot, so it's hard to advise you much more than this without seeing some specific hands.