Apple has a three year warranty which means yours may have run out or is about to run out.

If you still have time, get your keyboard replaced for free: https://support.apple.com/keyboard-service-program-for-mac-n... (it also means they have to replace your mobo and battery due to brilliant Apple engineering).

It doesn't fix the problem, but it resets the clock until they fall off again. In Texas, it was <48 hours between dropping my Macbook off at the Apple shop and receiving it on my doorstep.