Other than a complete power off, I know of no reset switch on any microwave ovens. I own a panasonic myself.
I would leave it unplugged for a while, at least 15 minutes or so, and leave the door open, to turn on the inside light (which won't light if unplugged but) so it might discharge any capacitors holding residual power to the circuit.
If it wasn't power protected, it could have taken a hit.
If it is plugged into a surge protector, they wear out. You might be able to make a claim on it through the surge protector manufacturer, if it has a warranty, and you have receipt. Surge protectors do wear out, and most unless they're the cheapest, will have a warranty that covers equipment. The wear out because the varistor which provides the voltage clamping during a surge become conditioned. Initially they clamp around 150V to 180V, but as they age from repeated surges, their clamping voltage rises until it no longer protects the equipment. Often you can tell, if the surge protector LED is blinking or intermittent, the company will replace the surge device if you make a claim on the protector, if it fails while in use, they usually cover the equipment, unless the warranty has run out, but many give lifetime warranties.
The reason some keys may have been working is because after a small surge, the logic states can go indeterminate, which means some work, and some won't. If it's not damaged, a full power off for some time may restore it to initial conditions.
Hope this helps. They should build in surge protection, and I think mind does have some; but, if not, I hope it's in warranty for you.
on Jul 04, 2017