SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71bd1b3269cf74a727bc653f635001b7945b4937eedd51f7a429c83f6df79974' 
  AND token = 'z0M32wXA/MCUzmQNQeVfvpiEp6jf9kuDU1JreOjeTf4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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