You should try to format the date and then compare it with the value
DATE_FORMAT("2019-01-16", "%Y-%m-%d")
You can try this:
select det.* ,uim.c_code from
cust_inv_det det
join u_stockiest_item usc on det.c_c2code=usc.c_stockiest_code and det.c_item_code=usc.c_stockiest_item_code
join u_item_mst uim on uim.c_code=usc.c_ucode
join u_item_mfac_mst mfac on mfac.c_code=uim.c_item_mfac_code
where DATE_FORMAT(det.d_date, "%Y-%m-%d") ='2019-01-16' and usc.c_stockiest_item_code='142193'