Is this video speed class V30 and rating A1 (i.e. the specs needed to film 4K)?

This is from from the description page on a photo website. Hope this helps.

SanDisk 64GB Extreme PLUS UHS-I microSDXC Memory Card with SD Adapter

Designed for microSD devices such as smartphones, interchangeable-lens cameras, drones, or GoPro action cameras that can capture Full HD, 3D, and 4K video, as well as RAW and burst photography, the 64GB Extreme PLUS UHS-I microSDXC Memory Card from SanDisk has a capacity of 64GB, is compatible with the UHS-I bus, and features a speed class rating of V30, which guarantees minimum write speeds of 30 MB/s. If your device does not support the V30 standard, this card also supports the U3 standard, which also guarantees minimum write speeds of 30 MB/s. Read speeds are supported up to 95 MB/s and write speeds max out at 90 MB/s.

Write Speeds of up to 90 MB/s MB/s

Capture fast-action photos or shoot UHD 4K video with write speeds of up to 90 MB/s MB/s to shoot more and transfer even faster. Quick read speeds of up to 95 MB/s save you time when transferring high-resolution images and UHD 4K videos.

UHD 4K Ready

With UHS Speed Class 3 (U3) and UHS Video Speed Class 30 (V30) ratings, this SanDisk Extreme PLUS UHS-I microSDXC card lets you capture uninterrupted 4K UHD and Full HD video. This makes it suitable for recording outdoor adventures, weekend trips, or sporting events without skipping frames.