No worries! Fake crate keys often emerge when players do not use their crate keys immediately, so they expire and turn into Fake Crate Keys. No need to fret about the message that appears. Simply destroy the keys (i.e. in lava) so that other players won't deal with it as well! If you need anything else, please feel free to let us know on the forums or create a ticket on the #help-and-support channel in our Discord and a staff member will help you out right away. Stay safe and healthy.