Yes, they can. 20% of ESL teachers are non-native speakers. In fact, many times non-native speakers are better teachers because they previously took ESL classes and know more about grammar structure than native-speakers. There used to be a time when native-speakers could show up without any training and teach English anywhere in the world but there is more competition and schools are realizing that you need to be qualified to be a good teacher.
You'll be fine as long as you don't have much of a foreign accent.