Your 2017 MBA has Thunderbolt 1 ports, so you'll be looking for a Thunderbolt 2 to Thunderbolt 3 cable or adapter.
MacBook Air (13-inch, 2017) - Technical Specifications - Apple Support
Thunderbolt cables are expensive regardless their flavor and the old Thunderbolt 2 cables are getting hard to find. Why spend good money to buy a cable that you are likely to use only for this data transfer?
The best option for transferring data from one Mac to another is to use an external drive along with the Time Machine backup application. Back up your Mac with Time Machine - Apple Support
In this case an external drive with USB-C connection and USB 3 or 4 capability is all that is required. And once your data is transferred, you can continue to use the external drive as the Time Machine destination for your new MBA.
Note: a USB-C to USB-A plug adapter may be used to connect an EHD with USB-C plug to the old MBA.