How can I disable shift + control + scroll zoom in chrome?
If I might say so, why are you using the 3 keys to switch between the tabs.

In Chrome it is enough if you use two keys to switch tabs.

control + tab

If however you prefer to modify the the Chrome shortcuts, visit this website

https://chrome.google.com/webstore/detail/shortcut-manager/mgjjeipcdnnjhgodgjpfkffcejoljijf