Search results are not a work, so no works-cited-list entry is needed. If you are referring to the results as evidence, you can simply name the database in your prose, as in the following example:

At first—to judge from the 190-odd results for the phrase in a JSTOR search at the time of writing—invocations of distant reading were concentrated in debates about world literature.*

*The quotation has been modified from Andrew Goldstone’s “The Doxa of Reading” (PMLA, vol. 132, no. 3, May 2017, pp. 636–42).