cql - Cassandra ReadTimeoutException on querying based on timestamp -

i have cassandra db table records

create table records ( id text, cachedtime timestamp, data list<frozen<recordtype>>, primary key (id, cachedtime)        , clustering order (cachedtime desc); 

recordtype udt , cachedtime clustering key , ttl each record 60 minutes.

we hitting readtimeoutexception, on querying below select query consistency level local_quorum replication factor 2.

select * records id= "11" , cachedtime <   com.datastax.driver.core.exceptions.readtimeoutexception: cassandra    timeout during read query @ consistency local_quorum (2 responses  required 1 replica responded)  

can me why hitting exception. please advise on query based on timstamp no lower limit cause performance issue?

please advise