Is it considered plagiarism if in the abstract, only key authors of frameworks used were cited and other peripheral concepts mentioned in the abstract were not cited but were cited in the body of the study?
That is not plagiarism. Only when you don't cite the relevant source materials at all, plagiarism comes into play. Such materials ought to be cited next to the relevant concepts. You wouldn't have to cite the references every time you repeat the concept.
Having too many citations in the abstract is something to be generally avoided. As long as you cite those references next to the appropriate concepts in the body of the article, you won't be considered plagiarising content.