Check the obvious spots first — bags, coat pockets, the kitchen worktop. If they're genuinely missing, call a local mobile auto locksmith rather than your main dealer. Covering Dorset, Hampshire, and Salisbury in Wiltshire, we can come to you wherever your car is parked — whether that's a car park in Bournemouth, a retail park in Southampton, or your driveway in Salisbury — and cut and programme a replacement key on the spot.
If you think they may have been stolen rather than misplaced, tell us when you call. Where possible we can recode your vehicle so that the missing key can no longer be used to open the car, though this is dependent on your vehicle's make and model and no auto locksmith can guarantee this in every case.