I have airlined recently. First trip was London Heathrow to Stockholm Arlanda. T2 with SAS. Terminal was pretty quiet and only 2 shops open. Masks were available if you needed them. Which you did to board and fly. Social distancing was a challenge during the boarding and disembarking process. No service, just a bottle of water.
Return was Stockholm Arlanda to Heathrow via Frankfurt with Lufthansa. More shops were open in Arlanda but only 1 terminal was operational. Ironically, it was here where social distancing etc was being enforced. Masks required during boarding. Only water on the first leg. 2nd leg, water and a sandwich. Frankfurt wasn't nearly as busy as it usually is, a few more food shops were open.
Heathrow is now checking temperature on arriving passengers.
I believe Luton Airport will have vending machines with masks available for purchase. Heathrow, they were free.