The process of sandboxing for websites is not governed by any specific rules or guidelines. However, it is generally observed that aged domains tend to avoid being sandboxed when ownership or hosting is changed. It's worth noting that even if a domain has been expired for a significant period, there is still a possibility of it being sandboxed.
Furthermore, having just one backlink does not significantly impact your rankings or provide a headstart in terms of search engine optimization. For a backlink to have a substantial effect, it would typically need to be of high quality and come from a reputable source such as a prominent website like NBC. However, even with such a backlink, it is unlikely to prevent sandboxing or significantly influence your rankings.
Now about backlink
If the backlink pointing to a domain is weak, it is understandable that Ahrefs might assign it a low Domain Rating (DR). However, even if the DR were to be as low as 10, it would not have a significant impact. This is because the calculation of DR is based on an exponential function, meaning it grows rapidly up to a certain point (e.g., around 30) and then requires increasingly stronger links to increase by just one point. While I may not fully understand the intricacies of the mathematical calculations behind DR, this explanation should provide a general understanding.
Ultimately, it is advisable not to dwell too much on the low DR and having only one backlink. If you are content with the domain you have acquired, consider restoring it if it is worth the effort. Otherwise, begin using the domain, and over time, it may naturally exit the sandbox. It's also worth noting that there is no guarantee of a domain getting sandboxed, as Google's algorithms and behaviors can be unpredictable these days.