Keep in mind that these two cars might have different wheel offsets. The offset is the distance from the hub mounting surface to the center of the wheel. If the offset of the Prelude rims is significantly different from the Civic EX rims, it might affect the stance of the car and potentially cause issues with clearance.
However, most aftermarket rims offer a range of offsets, so you can choose one that matches the specifications of your Civic EX to ensure a proper fitment. It's always recommended to consult with a reputable wheel and tire shop or automotive expert to confirm the fitment before purchasing and installing the Prelude rims on your Civic EX.