How to use Google Scholar to search key words in abstracts

There is no way to restrict the results in Google Scholar by citation number, to my knowledge. However, it is useful to understand that Scholar heavily weights the number of citations in deciding which results to return. For a broad search one can see this; the returned results will tend to be in order of decreasing number of citations. When narrow searches are done, as by using many search terms, this ordering is often not seen, presumably because the search engine finds closer term matches in obscure papers with few citations. Sometimes one can choose alternative queries which are broad enough to include the more heavily cited papers in the field.

Some insight into how the Google Scholar search engine works is available in this paper: Beel, J. Google Scholar's Ranking Algorithm: An Introductory Overview

It had been gone in redesign few months before you asked this question and most probably you had enough time to assure yourself it won't return ever.

One mitigation would be adding those keywords from topic to search query text. The other could be limiting search down to particular publishing site with site:example.com/path stem, if you know that info in advance.