There are a number of measures that can be taken initially there will probably only be a third of the number of people flying so prices will be three times higher. Terminal entry can be restricted to passengers only maximum two hours before departure. Social distancing in baggage reclaim might be possible given the level of passenger usage. Luton appears to have a problem with immigration though as from memory it doesn't have a large hall where you could snake people and keep them 2 m apart like some other airports.
Bear in mind I think we will be lucky to see 6 million pax this year and 9 million next at best though.