How to store search data in redis db for caching to gain maximum performance improvement - caching

Question

We are implementing a online book store where the user can search books by filter,price,
author, sorting etc..Since we have million's of records in database(mysql) the search query
becomes slow. SO improve performance we are planning to implement caching mechanism using redis . BUt i am struggling to determine how to store the search data in redis db.
For example:-
If the search criteria is below:
{
searchFilter:
[
{
"field":"title",
"operator" : "LIKE",
"value" : "JAVA"
}
]
}
Then we will fetch data from from mysql db using above json. Then we are storing the data received in redis server.
In redis server we are using above json as "key" and all the books as value i.e
:
{searchFilter:[{"field":"title","operator" : "LIKE","value" : "JAVA"}]} : booksList
Now say some other user again fired a search request as below
{
searchFilter:
[
{
"field":"title",
"operator" : "LIKE",
"value" : "JAVA"
},
{
"field":"price",
"operator" : "GREATER_THAN",
"value" : "500"
},
{
"field":"price",
"operator" : "GREATER_THAN",
"value" : "500"
}
]
}
Then again we will fetch data from from mysql db using above json. Then we are storing the data received in redis server so that for next request with same search critria
we will get data from redis cache.
In redis server we are using above json as "key" and all the books as value i.e
:
{searchFilter:[{"field":"title","operator" : "LIKE","value" : "JAVA"},{"field":"price","operator" : "GREATER_THAN","value" : "500",},{"field":"price","operator" : "GREATER_THAN","value" : "500"}]} : booksList
So my question is using the json search criteria as key in redis is good idea?
If yes, then for every search request criteia having any small difference if we store the data in redis then caching server will consume lot of memeory.
So what is the ideal aproach to design our redis cache server to gain maximum performance ?