Stop spotlight from spinning up hard drives

Hi,

My Mac boots from SDs and is usually super fast when searching and finding documents via spotlight.

However, I have a couple of external hard drives for backup purposes and Final Cut footage libraries.

The problem is that whenever those hard drives are connected to the computer (even when not using them), they slow down spotlight. Let's say I'm looking for a document on my SSD. When putting the document name into spotlight it'll freeze for 10 seconds until my external final cut hard drive has spun up and only show the result then.

Is there a way to stop spotlight from searching external drives or at least search the internal drives first and then only show results from the hard drive when available?

I have an iMac Pro running 10.15.5

Many Thanks!