Can I check warranty for my iPhone accessories like adaptor or wired headphones?

These parts are also covered by the One-Year-Warranty, its they came with the iPhone.

...

The Apple Limited Warranty covers your iPhone and the Apple-branded accessories that come in the box with your product against manufacturing issues for one year from the date you bought them. Apple-branded accessories purchased separately are covered by the Apple Limited Warranty for Accessories. This includes adapters, spare cables, wireless chargers, or cases. 

Our warranty is in addition to rights provided by consumer law. 

Depending on the issue, you might also have coverage with AppleCare+. Terms and Conditions apply, including fees. Feature availability and options may vary by country or region.

If your situation isn’t covered, you’ll pay a fee. If the issue with your iPhone is ineligible for service, you might pay the full replacement value.

Check your coverage status

Read the Apple Limited Warranty

Look up consumer laws in your country or region

...

copied from: iPhone Repair & Service - Apple Support

If you bought them separately, you should have the receipt and the warranty terms that came in the package.

Not all accessory can be checked by the serial number, you will have to check your purchase receipt and the date on it, to see when your warranty will expire.