The cheap wheel-lock sets are not key locks, they are just oddly-shaped bolts that need a special bit to torque on. They are all the same, and they are easily defeated if someone really wants your wheels. However, they are great protection against some dumbass kid who wants to play a prank.
My '87 924S had wheel locks with keyed cylinders, but the PO lost the key, so they had to drill out the locks when I put new tires on. Drilling out the locks was easy, so even the kind with a unique key are easy to defeat if the theives know what they are doing.
Again, they are a great protection against a prankster or someone who isn't intent on getting those specific wheels, but as with anything else, if someone really wants your wheels, they will get them.
ZV