SELECT 
  feature_id, 
  variant_id, 
  value, 
  value_int 
FROM 
  cscart_product_features_values 
WHERE 
  product_id = 3325 
  AND lang_code = 'en'

Query time 0.00042

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 74 Using where

Result

feature_id variant_id value value_int
176 6265
176 6272
30 6131
178 6317
42 149
127 5895
128 5899
129 5903
135 5967
135 5968
24 107
136 5972
135 5963
176 6268
176 6267
136 5976
135 5964
176 6264
176 6269
176 6266