Here is a quick update on how-to get a fully working USB 3.0 ports on some old laptops like the Lenovo ThinkPad T420 (will suit many other ThinkPads and other makes / models). This one is the cheapest possible USB 3.0 ExpressCard I can found on the internet (AliExpress), keep in mind that there’s two different sizes of the ExpressCards – 34mm and 54mm (purchase according your laptop specs).
It works surprisingly good for a cheap Chinese hardware, installed on the ThinkPad T420 with Windows 10 and it was found immediately by the OS (no drivers needed), anyway the USB 3.0 ExpressCard comes with a CD with drivers just in case. The card features FL1000 / NEC D720202 chip inside so it should work quite well, the transfer speed test I made with an external 1TB HDD shows very good speed difference compared to the laptop’s USB ports: USB 2.0 port copy speed ~20MB/s compared to the USB 3.0 port ~110 MB/s (however the speed is limited due to the HDD).
Overall you can get that exact one USB 3.0 ExpressCard for your laptop and give it some new tech upgrade, the build quality may vary from model to model – in my case it fits quite tight in the ThinkPad T420, the USB ports are a little bit loose, but they keep what’s connected inside. You can buy it from AliExpress for about $10 with free shipping (do a search on the website and found the cheapest one possible).