For retrieving document(s) by ID, the best approach is to use filter parameter from MS Documentation.
Example:
<url_SP_Site>/_api/web/lists/getbytitle('[Name_Document_Library]')/items?$select=Id&$filter=Id eq '[Id_you_search_for]'
If you want to search for multiple documents IDs, you can add and
or or
operators (I think you have more operators, see the documentation).
Examples:
<url_SP_Site>/_api/web/lists/getbytitle('[Name_Document_Library]')/items?$select=Id&$filter=Id eq '[Id_you_search_for]' and Id eq '[Another_Id_you_search_for]'
<url_SP_Site>/_api/web/lists/getbytitle('[Name_Document_Library]')/items?$select=Id&$filter=Id eq '[Id_you_search_for]' or Id eq '[Another_Id_you_search_for]'
After that you can use expand parameter with file value to have the relative URL:
[url_SP_Site]/_api/web/lists/getbytitle('[Name_Document_Library]')/items?$select=Id,File/ServerRelativeUrl&$expand=File&$filter=Id eq '[Id_you_search_for]' or Id eq '[Another_Id_you_search_for]'
When you get the response encoded in JSON Format, you can access easily with:
d/results([Your_Index])/File/ServerRelativeUrl