Lock cylinder, lock cylinder set, ignition switch. These are all different parts.
86-89 Ignition Lock Cylinder:
69057-32121; $102.44
90-92 Ignition Lock Cylinder:
69057-14130; $101.55
These will come with new keys. If you want to keep using your original key, you'll need to get a locksmith to re-key the new cylinder to your original key. You'll probably want to get a new key cut to your original key code though, and not use your old worn out key. Your original key code is on the paperwork for the car, or alternatively stamped on the exterior of the RH door lock cylinder. You may be able to get the code from a Toyota dealer in your area, though the car may be too old. In Canada, we cannot get key codes for vehicles as old as the MK3.
Jeff