SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '739ab141c7a56e8b870fe34a7dea1b8419b69d603360dd25ed2360639167b972' 
  AND token = '2YwEiafrCWPpJ5z/KV/vGL0QkTgmGp9RFiOXWlMnOoU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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