They’re called “shave keys”. Older vehicles with double cut keys wear down inside the lock cylinders and the keys wear down too. Thieves will have a ring full of well worn keys for target makes, usually pre-2001 Fords, Toyotas, and Hondas. Usually one of the dozen keys of a particular type will pop the door and turn in the ignition and they’re off. Rekeying an older vehicles isn’t cheap and they prey on that.