"key to explain" is correct and usable in written English.
It is typically used to reference a particular piece of information that aids in understanding a more complex concept. For example, "The professor provided a key to explain the underlying principles of her argument."
Include a key to explain each surface feature you choose to describe.
As well as selling your charity its key to explain what is in it for the trustee – what skills will they gain and what experiences will they have?
The unidentified nitrosyl species might be the key to explain the dependency of DRIFT spectrum of adsorbed NO on the pressure of sulfiding.
We conclude that the study of changes in all the spatial attributes considered within the same case study is a key to explain ecological consequences in mosaic cycles or in stochastic dynamic landscapes that emerged from the interplay of several processes, and to predict and explain their spatial and temporal characteristics.
We model the trade-off between discipline and flexibility in the design of trade agreements, and argue that recognizing this trade-off is the key to explain the observed patterns in the tariff binding commitments and applied tariffs under the WTO.
We submit that, in this case, a technological ideology is key to explain the ability to explore novel possibilities, or the technology of foolishness according to James March.
That simple observation holds the key to explaining the post-79 era in British politics.
Is the fundamental reference rule for "I" the key to explaining first-person self-reference?
Baum finds that American liberalism is the key to explaining how this happened.
Religion is the remaining key to explaining humans' remarkable social networks, Dunbar thinks.
The key to explaining Brooks is her knack for forging well-targeted friendships.
