。
Equality is protected by the constitution.
Literal
Equality [topic-は] constitution [by-で] protected is.
守られている is 'is protected,' the passive of 守る ('to protect, defend') with ~ている for the ongoing state. 守る is broader and more general than the closely related 保障する ('to guarantee, formally secure'). Both are natural collocations with 憲法 ('constitution'), with 守る emphasizing active defense and 保障 emphasizing formal guarantee.