SELECT 
  feature_id, 
  variant_id, 
  value, 
  value_int 
FROM 
  cscart_product_features_values 
WHERE 
  product_id = 8312 
  AND lang_code = 'de'

Query time 0.00046

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 56 Using where

Result

feature_id variant_id value value_int
30 5773
28 5776 2.800
32 0 599.000
41 0 249.000
129 5904
128 5899
127 5895
147 6065
148 6074
148 6080
148 6078
148 6077
148 6076
117 5871 0.100
178 6328