Oh don’t worry, most keyboards have a maximum of 5 volts inside.
I know this is humorous, but... While computers generally run DC voltages of 5v (or 3.3v or 12v) bad things can still happen. I learned the hard way that when you see an electrical engineer with a screwdriver, RUN AWAY!
I was installing a computer network at a packaging firm, and they had one of their EEs wiring up the cubicles. Well, this guy managed to wire a hot ground! When I reached behind the computer to connect the BNC-T connector to the thinnet bus, my wrist contacted the chassis (using the hand-in-pocket rule, from habit) and I got one hell of a burn, and the thinnet cable was ruined at the T connector.
Mark