This is basically what a security key (e.g., yubikey) is? I'm actually surprised I can't get a door lock that can be opened by one, yet. Could even be NFC cap

This is basically what a security key (e.g., yubikey) is? I'm actually surprised I can't get a door lock that can be opened by one, yet. Could even be NFC capable, so that you don't have to plug in anything. Similarly, this is effectively what many car keys are, nowadays.