[koide]

You could take only the one or two keys needed to get in, tied up with a tiny bit of wire. Leave the keychain and rest of junk keys you might have.

[whichdan]

What I do is keep my keys on ~3 different keyrings based on what they're for, and a snap hook to keep them all together. Makes it easy to mix-and-match, and you don't have to fumble with a wire.