SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75c6c792b0f135d9fcb7f30a25f1b9217d7966179b7b5762309cffa8f5e836e2' 
  AND token = 'JZ6xWMi5KuBYwv9+jZvv3urEtO8RcgwizJ5LrY8+dvc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}