The only Carbs really are the bun of your choice and maybe a few depending on the cheese. If you prefer a hard cheese, grate and sprinkle it on the eggs rather than tear pieces of the soft cheese slices.
Gluten Free buns don’t quite cook up like their flour counterparts but heating them in a skillet does help.
It’s more about remembering how delicious and easy this breakfast sandwich is, rather than Carb counting.