I have misplaced my keys more times, than I would like to admit!
So I now have several bunches of the same.
I also have one car key and house key hidden in my handbag.
(only because I get them made for free my son's are locksmith's)...but, even if they were not....you should always have more than two sets., of keys.
It may sound in excess, but it's really not.Children can loose one pair...you the other ...and Bingo! you still have that last set left.
Lot more cheaper than getting a Locksmith out, and having to have all those keys made again.That can run into a good few hundred dollars, no joke.!