SELECT 
  feature_id, 
  variant_id, 
  value, 
  value_int 
FROM 
  cscart_product_features_values 
WHERE 
  product_id = 10211 
  AND lang_code = 'en'

Query time 0.00072

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 112 Using where

Result

feature_id variant_id value value_int
178 6308
23 101
23 103
30 240
42 145
21 96
19 241 0.700
24 107
127 5895
128 5899
129 5902
134 5962
20 6058 1.100
152 6090
152 6092
152 6093
152 6094
149 0 5702328324886
152 6102
152 6105
152 6106
152 6095
152 6096
152 6097
152 6116
152 6118
152 6089
152 6100
152 6101
22 99