SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce7874fd119674867421781010b7ea3cc228a73bc67ed6d84c6f74c9b195e1b3' 
  AND token = 'UZXiilSwNr/Kp7k1Rzd3nWT0051+6I60J6zW5K7ByNU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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