SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46615cb893a488eed786c321bf8bb59401c426e12d684f4b5f4dc47e6c504b5f' 
  AND token = 'LNqbTLE5dLlTyg2mvN3nnIdvRXUgAI0XwmqtTOKWg9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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