SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '541cd04d15a316615efe79e88aa3ac8ff81a1321583de85cb8f91423bf57da7d' 
  AND token = 'ASm+Areuqu0JcFs7FIbsueMPpQZtSTP5ICm908ob3rA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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