SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1a89510aeda99927b68ab55f5fe0014f95295159db51a10924de64c3cba3710' 
  AND token = 'LyWbsvVKiV5KY9WsAdWkxLZDV9pFNXqPYWDqxKfUNbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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