Hi @jeanlfernlund
The shelf life of a Lithium coin cell battery is ~10 years, if stored at normal room temperatures.
All batteries lose a bit of power over time so whilst it should work perhaps it won't work for another 5 years.
Just verifying that you installed the battery the correct way in the key and not upside down i.e. reversed?
Here's the [guide|40413] guide that may help.
If you have a DMM (digital multimeter) check the voltage of the battery. It should measure 3V DC. If it is <2.5V DC then perhaps the key won't work