Yes and No.
IF you would be getting a refund, then you have up to three years to file and still claim that refund. After three years, your refund would not be returned to you.
HOWEVER, if you fail to file and you OWED more taxes, then you would be charged late fees and fines for not filing and paying the rest of your taxes owed on time.
For a lost W-2, you can try contacting the employer. If that doesn't work, you should be able to get the forms from the IRS.
https://www.efile.com/what-are-the-penalties-for-not-filing-a-tax-return-or-not-to-pay-taxes-IRS-penalty-list/