Lexus RX 2010-15 :: RX350 Push Button Start - Key Lost Somewhere Inside The Vehicle

I am very puzzled with my new 2015 Lexus RX 350 , I parked my car at the gas station and suddenly noticed that I dont have my key on me and couldnt find it inside the car anywhere. I thought I dropped it somewhere outside but to my surprise when I tried starting my car it started fine assuming the key was some where close by.

I tried stepping out and to lock the car and got a message the key is inside the vehicle so car wont lock. I was able to start the car and drive it home about an hour drive car never complained about key not detected message. I called the dealership and they told me car will keep running if you drop the key outside while the car is running but after 15 mins of driving it will give a message key not detected.

I am locking the car now using the second remote but its risky to have the car in such a condition as any one can drive it away if they open the lock somehow. I have looked every where under the seat, in between the centre console and seat, under the seats key no where to be found. Could it be possible that key was dropped outside and the car is malfunctioning that its allowing me to start it and drive it without complaining.