[daigoba66]

No. The zone file lives on the nameserver (DNS server) which Route 53 provides. Namescheap registers a list of nameservers for your domain with the TLD.

An over simplified example for looking up "news.ycombinator.com":

1. First query the TLD nameserver for all ".com" domains asking for the authoritative nameserver(s) for "ycombinator.com".

2. Next query that nameserver for "news.ycombinator.com".

[sparagi]

But, the first entry point is namecheap. The domain is at Namecheap, so it will not find the zone file at Route 53, if Namecheap does not send it there. Right?

[colmmacc]

No, registrar's are your portal to updating data in TLDs, but those TLDs are each operated separately. .com and .net are operated by Verisign, for example.