SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1235ed69a368cdb5458859582e81bb24cd3b088b04a7614ffeb087586c36cb8' 
  AND token = '0hMl4yKljqLY0c0Vyl+Kfi3Ou7dYrLEufWA1xAuFN3I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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