SELECT 
  variant 
FROM 
  cscart_product_feature_variant_descriptions pfvd 
  INNER JOIN cscart_product_features_values pfv ON (pfv.variant_id = pfvd.variant_id) 
WHERE 
  pfv.feature_id = 107 
  AND pfv.product_id = 16309 
  AND pfv.lang_code = 'en'