How to Stop Automatic Date Conversion in Looker Filters

[lookeruser8888]

I have date dimension, and I have a filter based on date to get data earlier than certain date. However, I noticed that looker automatically use wrapper function (TO_DATE) which prevents snowflake to leverage the index and make the query slower. I tried to use date_raw, but this won't appear in the explorer. Anyone knows solution for this? Thanks. 

QUERY generated by Looker:
==========================
WHERE (view."BUSINESS_DATE" ) >= (TO_DATE(TO_TIMESTAMP('2020-11-16')))

Dimension in the model file:

dimension_group: business {
type: time
timeframes: [
raw,
date,
day_of_week,
day_of_week_index,
week,
month,
quarter,
year
]
convert_tz: no
datatype: date
sql: ${TABLE}."BUSINESS_DATE" ;;
}