There's nothing wrong in asking. A typical request would be written like this:
Subject: Request for Expedited Review of Submitted Manuscript - [Manuscript Title]
Dear [Editor's Name],
I hope this email finds you well. I am writing to kindly request your assistance regarding the review process of my manuscript titled "[Manuscript Title]," which was submitted to [Journal Name] approximately 2.5 months ago.
Firstly, I would like to express my gratitude to the reviewers and the editorial team for their time and effort in evaluating my work. I understand the importance of a thorough review process, and I appreciate their commitment to ensuring the quality of publications in [Journal Name].
However, I find myself in a unique situation where an exciting career opportunity has presented itself to me. I have been offered a junior scientist position at a national laboratory, which aligns perfectly with my research interests and long-term goals. The condition for securing this position is to have a first/single author publication, and the deadline for this opportunity is rapidly approaching at the end of this summer.
Given the time-sensitive nature of this career opportunity, I would be immensely grateful if it would be possible to expedite the review process for my manuscript. I understand that this is an exceptional request, and I assure you that I value the integrity and rigor of the peer review process. However, I believe that a faster review turnaround would provide me with the chance to fulfill the publication requirement and secure the aforementioned position, allowing me to contribute significantly to the scientific community.
If it is feasible, I kindly request your support in expediting the review process or providing any guidance that may facilitate an earlier decision on my manuscript. I am open to any suggestions or alternative solutions that would allow for a timely evaluation without compromising the quality of the review.
Please feel free to contact me if any additional information is required or if there are any updates regarding my request. I sincerely appreciate your understanding and consideration in this matter, and I remain committed to working closely with the editorial team to ensure the integrity and excellence of the publication process.
Thank you very much for your attention and assistance. I eagerly await your response and look forward to the outcome of the review process.
[Your Contact Information]
Since it's long, it'd help to highlight the important sentences with a yellow highlight or bold letters.