SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41f47b523a640319893072f09c53282d5b2ae45ae5946ca87047dc12dbca9c12' 
  AND token = 'Jqe+UxyyLA7YeUQWqJfIHwFvi7sEPZq15GStdAbw5+0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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