Airport X-rays vs Apple Magic Keyboard

No, your battery will not be damaged. An airport x-ray will have no detrimental impact upon your iPad or its associated Magic Keyboard and your accessories.

Be aware that the Apple Magic Keyboard for iPad has no internal battery of its own - but is entirely powered by the iPad to which it is connected via the iPad’s smart connector.

Magic Keyboard for iPad attaches directly to iPad and closes to create a thin cover (supported models). It includes a built-in trackpad, which you can use to move around the iPad screen, open apps, and more. Magic Keyboard for iPad requires no batteries or external power (but you can connect it to power to keep iPad charged).

Extracted from this support page:--> Apple external keyboards for iPad – Apple Support (UK)

Regards

Giulio