Yes, technically, getting indexed and getting ranked are two separate events. Google’s search engine actually calculates your rank during query runtime. That means after each search query request Google will instantly rank the results for your query. It’s during the process of being indexed that Google identifies which keywords are relevant for your page and precisely what your relevancy score is for each of those keywords.
So, while technically you are not ranked until after a search query is performed, your relevancy score has already been calculated prior to that event and it is simply a sort function that dynamically ranks your page. The score that determines where you will rank is calculated as part of the indexing process. In the past, Google did the relevancy scoring separate from the indexing process, but they found it to be more efficient to combine these steps into a single process. So once your page is indexed, the signals used to rank your page are already calculated except, for those that execute during query runtime.
The reason you are not seeing your page ranked for your target keyword after indexing is because your page’s relevancy score is not yet high enough to show in the top 1000 results, which is the cutoff for SERPs.
Relevancy scores are weighted at query runtime by PR, Trust and other factors that may apply to your particular query. A brand new website will typically have very low PR and Trust factors that must be earned. Promoting your pages by building meritorious backlinks from quality established pages will accelerate the process of earning PR as well as Trust.