Is the equal pay act included in the constitution?

No, the equal pay act is not included in the Constitution. Actually, the very use of the Word "Act" means it is a statute, not part of the Constitution. The Constitution has a general requirement of equality of treatment, but that requirement is not absolute. It is not in the Constitution because the Constitution is a fundamental powers document. From those powers come the right to make laws governing individual situations, like pay, voting, segregation, etc. It could not cover every instance of every area where an issue of equality of treatment arises.