Here are the keys to my car- why plural?

Hi,

Here are the keys to my car.

I’m just curious about why we use ‘are’ and ‘keys’ here. Normally, a person has one car so s/he has the key of his/her car. How about “here is the key to my car.”? I found some usage like “Lost your car keys?” or “I lay my car keys down on my desk.”

What do you think? Are they simply rich enough to have more than two cars? Please let me know!

Thanks in advance,
sweetpumpkin

In my experience, people say “here are my car keys” with reference to one car.
Usually you have one ignition key and one door key, although they may be combined into one single key.