I also had a 1989 Toyota pickup that the key was broken in half in the ignition when I bought it used. All you had to do was insert the other half (or a screwdriver) and turn it to crank it, then remove whatever you used to crank it with.

Every now and then I'd leave the half key sticking out of the ignition by accident, and it would always just fall out going down the road and land the whole keyring in the floorboard.