Keys are sticking or ghosting?

Hi, I had an issue with keys being stuck on, or ghosting. It was not obvious from a physical inspection that any keys were stuck. Perhaps there is dust beneath? I was in a dusty environment for several months.

I have temporarily fixed this problem by turning on Accessibility -> Keyboard -> Slow Keys.

I am bringing to the genius bar tomorrow, but would like to pose this question here in case there is a diy solution. I will update this answer if they tell me what's wrong.