SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a1a3fab22deb27e82f307132aac5479539231021ef36b55b4adbece881227e9' 
  AND token = 'CO2W/WH+wHeVNbgRH6Kb7IAwdAMiOnzrIlKk2NAbAD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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