I would look for something else other than a scone, I'm afraid. All recipes I've seen for scones use refined white flour (high GI), fat, and loads of sugar. Even if the scone was low fat, I"d avoid the white flour and the sugar.
I would have suggested to try and eat a wholemeal one intstead but the nutritional value of that is basically the same as a plain one.
I'd suggest ditching the scone for something which wont send your blood sugar soaring and then crashing leaving you feeling very hungry before dinner time. Healthier choices would be yoghurt, porridge, muesli, fruit, eggs, wholegrain bread.
The latte should be fine as long as its not full of sugar and syrups.