Place the chicken thighs and buttermilk in a bowl. In a separate bowl, add the flour, garlic powder, onion powder, paprika, pepper and salt, and mix to combine. Dredge each thigh in the flour mix, then shake off any excess flour and carefully place in the oil. Fry until golden, 7 to 8 minutes. Remove the chicken to a paper bag or paper towels to drain excess grease and immediately season with salt.