SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f07f1776def2bb98c5c45bf267b381f1ca9965ae73458b30a01c4559c42f6f04' 
  AND token = '0uGZjY4LElK4nwRoLh+NkP8Ogqsn1Kgjg5/sR/4EQJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00069

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}