Look at the driver’s door. Does it have a keyhole? Then there’s a key...
I haven’t personally seen a car without a key hole, but I can’t say I’ve looked terribly extensively, particularly at high end or ultra modern cars. But the three-four times I’ve been told “my car doesn’t have keys anymore!”, it did. Usually with a subtle lever on the key fob to release it.
+1 on
@Manatee Diver : get a copy made and put it somewhere on your person. For cars that ‘can’t lock the keys in’: use the mechanical key to lock the door as you walk away...