Many of the mueslis you buy in the shops contain lots of dried fruit which really increases the sugar and therefore carb content. Why not try making your own so you can leave this out and add other healthy ingredients instead.
Low Carb, Wheat free Muesli
100g porridge oats or millet/quinoa flakes
50g ground almonds
2 tablespoons each of chopped brazil nuts, pumpkin seeds, sunflower seeds, sesame seeds
Mix together all the ingredients and serve with a tsp of honey and some milk or with some natural live yoghurt and some fresh fruit (Berries, chopped pear or grated apple)