SELECT 
  feature_id, 
  variant_id, 
  value, 
  value_int 
FROM 
  cscart_product_features_values 
WHERE 
  product_id = 8891 
  AND lang_code = 'de'

Query time 0.00056

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 111 Using where

Result

feature_id variant_id value value_int
24 107
30 240
42 145
22 99
21 95
178 6308
127 5895
128 5899
129 5902
134 5962
152 6106
152 6105
152 6102
152 6101
152 6118
152 6100
152 6097
152 6096
152 6095
149 0 5702326550607
23 101
23 103
20 6052 1.300
152 6094
152 6093
152 6092
152 6090
152 6089
152 6116
19 93 1.100