Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Krabi to London Heathrow Airport as you normally would.
Located just 8.7 km from the city centre, Krabi is the airport most travellers will use when flying to London Heathrow from Krabi. Booking flights from Krabi (KBV) to London Heathrow should be relatively easy as there are 0 daily outbound flights to London Heathrow from 0 different airlines.
Yes, there are multiple flights from Krabi to London Heathrow Airport for under ฿30,200. The cheapest flight booked recently is on Multiple Airlines for just ฿30,189, but on average you can expect to pay ฿34,958.