How to make Solr synonyms work with KeywordTokenizerFactory?

Question

I have a field with KeywordTokenizerFactory in both analyzers because I need to search the docs those begin with a query phrase like "Lorem Ipsum" so I can search like q=myField:/Lorem Ipsum/ . The result must match the query exactly, it must start with Lorem and end with Ipsum with no words between them. At the same time I have a synonym for Ipsum - Dolor . This way when I search "Lorem Ipsum" I want to find documents where myField field contains only "Lorem Ipsum" or "Lorem Dolor" .
I can't split the phrase when indexing because in this case I won't be able to make sure to find only documents those start and end with words I need. I don't know Solr well and really stuck here.
Maybe I miss something and I can get the same result another way?