Both Thomas Aquinas and Martin Luther King Jr. agree on a certain fact: both men argue that not every law is equally valid. In order to answer your question, you would need explain that both men differentiate between just and unjust laws. In "Letter from Birmingham Jail", Martin Luther King Jr. refers to Thomas Aquinas’s theory. King explains to the reader that there are two types of law:

a just law is a man made code that squares with the moral law (...). An unjust law is a code that is out of harmony with the moral law.

In order to decide whether you agree with this or not, I would suggest you think a bit more about the implications of this statement. If a law is a just law, then it is basically a law that reflects God’s will. However, if a law is unjust, then it is against God's will. As a consequence of this, it would be against a Christian's belief to follow or obey any law that is in contradiction to God's law.

You could use World War II as an example to show this more clearly: when Germany introduced laws to discriminate against Jews during World War II, these laws were clearly unjust laws. They were in total contradiction to God's will. Therefore, according to Thomas Aquinas and Martin Luther King Jr., people should have refused to follow these results. In fact, a lot of suffering could have been avoided if people had not blindly followed these laws.

For this reason, I would definitely argue that civil disobedience can be justified if a law is genuinely unjust.