MBP 2013 becoming unresponsive to keyboard and mouse

My machine is a 15" Late 2013 MBP Retina. My OS is Yosemite 10.10.4.

I have a recent issue where my machine is intermittently becoming unresponsive to the keyboard and mouse. It's happening on average about twice a day at the moment.

I use a USB keyboard and mouse, plugged in via a USB hub.

The screen looks fine, the cursor is still flashing, I can plug the charger in/out and the battery symbol changes accordingly, the screensaver will come on fine, new email still comes in etc, so everything seems ok except my keyboard and mouse no longer work.

It also affects the keyboard and trackpad on the laptop itself. I press the caps lock key on the laptop keyboard and the green indicator doesn't come on.

The only key which works, luckily for me, is the power key on the laptop keyboard. I can hold that down and restart the machine. Nothing else works.

I've tried plugging the keyboard and mouse in directly (albeit only after the issue has started happening), I've reset the PRAM, I've closed the machine for 5 minutes and come back, nothing seems to fix it other than a reboot.

I've looked through the logs (after restarting) at the time it starts happening but nothing stands out.

I only recently moved to a USB keyboard and mouse and this issue only started happening since then. I only started using the USB hub at the same time too. I also started putting the machine on an MStand (although I can't imagine that would affect anything).

If it's one of the USB devices (or hub) causing this then it seems odd to me that it would also affect the keyboard/trackpad on the actual machine.

I've seen couple of other threads where people have something similar but nothing exactly the same and no definitive answers. Has anyone had a similar experience? Is there an obvious culprit out of the things I've changed recently which would cause the input devices to stop working?

Any advice appreciated.

Some more info: I'm pretty sure it's only happening when trying to do lots of scrolling with the mouse scroll wheel. I used to use the infinite scroll feature on the mouse a lot but noticed that's when the issue was occurring. So I switched to regular scrolling i.e. the clicky scroll wheel and it's happening much less frequently. It's happened once in the last 3 days whereas before it was at least once per day.

Feels like some kind of driver issue but the logitech software is up to date (v3.9.1).

Still hugely frustrating.