I'm trying KDE 5 and I'm spending significant amount of time looking at the System Setting shortcuts to find the name of the feature associated to a given key shortcut. Some shortcuts are interfering with some applications, where I cannot use the application feature I want because KDE have some feature associated with that shortcut.
Is there a way to search through KDE shortcuts list by the specific shortcut?
Yes, and it is straight in your face. Though, it might be slightly inconvenient to use if you do not know the name of the keys.
Lets say you want to search the shortcut associated with Ctrl+B; you open System Settings, then navigate to Shortcuts, and just type in the search bar: Ctrl+B
You will see the list of shortcuts filter by this regex.
tl;dr: In search, TYPE the key combo you want to find.
And, finally because a picture is worth a thousand words:
On more information from the comment, what you want to change ISN'T a keyboard shortcut (which consists only of keyboard strokes), but a window behaviour (changing behaviour of Alt+LClick on a window). That is in Window Management.
Change the Left Click action to Nothing.