SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '883df8b90412285416cd9a36a404a0990254771c89904cba2be5a4e6bf1704f4' 
  AND token = 'j05RYm79VrnGlU9N7iQu6J46bCkav7vWiUj5qLsbkGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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