Print only text between two special characters which contain specific word

In this file, there are many { and }

But I need to print only text between { and } which contain only HOST

Keep into consideration that context is unknown value as it might be (prod,dev or test ... etc)

Quote:

[[{"Key":"PORT",context:"5436"},{"Key":"HOST",context:"prod"},{"Key":"ADD",context:"location"}]]

Here, I need to print only:
Quote:

{"Key":"HOST",context:"prod"}