AVX is NOT a requirement, nor does it say they won't support 13 year old CPUs. i-5 is the miminum. I have a Xeon 5660 that is i7 based and faster than a lot of modern CPUs but can't run because they made the A310 dependent on a function that isn't required as you can see below.
SYSTEM REQUIREMENTS
MINIMUM:
Requires a 64-bit processor and operating system
OS: Windows 10
Processor: Intel i5-4460 | AMD Ryzen 3 1200
Memory: 8 GB RAM
Graphics: NVIDIA GTX 770 | AMD Radeon RX 570
DirectX: Version 11
Storage: 150 GB available space
VR Support: SteamVR, Oculus PC, or OpenXR. Keyboard and mouse required
RECOMMENDED:
Requires a 64-bit processor and operating system
OS: Windows 10
Processor: Intel i5-8400 | AMD Ryzen 5 1500X
Memory: 16 GB RAM
Graphics: NVIDIA GTX 970 | AMD Radeon RX 590
DirectX: Version 11
Storage: 150 GB available space
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