Some car manufacturers see fit to not to individualise the locking nuts so that you can just get another wheel nut key from another car of the same make and it'll work.
However, if your locking wheel nuts are aftermarket ones then they are very likely to be individual. They come with a code so that a replacement key can be obtained from whoever makes them.
Except the keys are a lot more harder to obtain than a new wheel set for £25.
There are a few universal applications. Thread pitch, and whether they carry a washer for alloy wheels without steel inserts are the two main differences.
a few years back i had a ford escort xri and in the ash tray there was a special socket for the alloy wheel nuts (apparently, i had no idea what it was for when i bought the car)