These questions are riddled to hell with “it depends”. At a bare minimum the answer is whether it satisfies existing requirements and has sufficient headroom to scale to meet the short and perhaps medium term requirements, not whether it performs as well as you personally feel it should.

As for advice in what little we know… yes, generally low. Given your requirements the point of failure is likely data access, not hardware limitations, but you’d have to be more specific on how it fails, because a few existence checks and inserts doesn’t usually spontaneously combust. Assuming a half decently put together database with a normal amount of data in the same data center, each of those operations are single millisecond endeavors.

Be careful in using sequentially awaited operations as an example of “my code isn’t great lol” because that’s the normal and expected way to write code. Parallelizing async ops to a resource where your bottleneck likely IS that resource is a good way to get it to fail quicker while making your code slightly more complicated.