The poem sets two scales of time side by side. The first line gives us something vast: the "infinite crow of time," a harsh, almost mocking image, with the night desert stretching out beyond it. Against that emptiness, the poem places a small, delicate creature, the moth of the title.
The second half turns on an "if." If love will go to any length, take every turn, just to find a moth, then the speaker, with a heart of their own, has only "a while." That last phrase lands quietly. The speaker seems to recognize how brief their time is, and perhaps how urgent it makes love feel.
The mood is hushed, a little lonely, but not despairing. The poem suggests that searching is worth doing precisely because time is short. The desert is huge and dark, yet the image of love winding its way toward something so small and fragile gives the poem its tenderness.