Since we normally deal with reality here.... I would like to mention some REAL things about keys.
One never knows when a belt might fail, or you might enjoy too much ice cream and put on a few pounds. Either way the belt needs to come off, or be adjusted. A key MUST remain accessible. There are multiple methods to achieve this, but do not send all your keys away.
Note: I have had my belt fail twice (metal fatigue) and that required immediate removal. Not to mention the time my back went TOTALLY OUT. My back started swelling up. It was almost impossible to just climb the stairs from the basement to the 2nd floor to get the key.... Just remember weird stuff happens...
I can discuss various ways to share/secure keys if you are interested.