SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef910cb86c7ad8266c8e748c10cbad704cc691b01133e7d4b6229084f58f9c49' 
  AND token = 'dwmOXR5OxTJS4Iqhu5zGD5UFIRVEtMpgZ1OQtiYVadY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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