The worker who learns the closing routine is usually the one who gets trusted with the keys.

Closing is where trust actually gets decided, because it is the part done without supervision and with real consequences: cash, locks, alarms, a till that has to balance. Learning it says you can be the last person in the building, which is a much larger claim than being good on a busy shift. Keys follow responsibility rather than seniority.

Ask to be shown the close, and write the steps down the first time instead of trusting your memory. Do it exactly as written for a month before you get clever with it. Being the person who can lock up is how you end up getting offered more.