SELECT 
  feature_id, 
  variant_id, 
  value, 
  value_int 
FROM 
  cscart_product_features_values 
WHERE 
  product_id = 10967 
  AND lang_code = 'en'

Query time 0.00047

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cscart_product_features_values ref lang_code,product_id,product_id_idx,product_feature_idx product_id 3 const 106 Using where

Result

feature_id variant_id value value_int
128 5899
42 145
30 6131
152 6095
127 5895
134 6238
152 6105
152 6094
152 6092
152 6096
152 6089
152 6088
129 5902
178 6317