How to expire a pass in Apple Wallet?

Does anyone know how to expire a pass in your wallet? A flight I took 2 months ago is still showing as active in my wallet, so whenever I go to pay for something my flight ticket comes up instead of my default card. I've been told I can just delete the plane ticket but I don't really want to do this as I like to store all my old flights to look back on, to remind me of all the places I have been.

Bit of an odd one, so any help would be amazing.