What is the smart way of reading the research papers?
It might sound like cheating, but reading an abstract and possibly skimming the introduction and the conclusion is absolutely enough for a normal essay citing a research paper.
Still, if you are writing the analysis of a research article or use it doing your own study, reading should be more thorough.
As a rule, you will have to respond to questions related to the assessment of
(1) literature review,
(2) research question and hypotheses,
(3) methodology and sample,
(4) presentation of the findings, and
This is why I recommend to combine reading with writing, that is to outline how many questions in relation to the research paper you have and read a new section after you have written answer related to the previous.
If you know how many words you have to write on each point, it automatically guides your reading and you will not spend too much time on the details if you have already covered the most important information in the required word count.