SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be0ab9dc5856bb1fe6d9545dfbf372ea53155fa257f7b697fcaf7ab278bef733' 
  AND token = 'bGrinljar89LCvSZlx6LTxEXh4FfEo7Q+ZdoqZVsXb8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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