SELECT 
  pfv.feature_id, 
  pfv.product_id, 
  pfv.variant_id, 
  fv.position, 
  fvd.variant 
FROM 
  q_product_features_values AS pfv 
  INNER JOIN q_product_feature_variants AS fv ON pfv.feature_id = fv.feature_id 
  AND pfv.variant_id = fv.variant_id 
  INNER JOIN q_product_feature_variant_descriptions AS fvd ON pfv.variant_id = fvd.variant_id 
  AND fvd.lang_code = 'en' 
WHERE 
  pfv.feature_id IN (73) 
  AND pfv.product_id IN (
    2988, 2992, 2997, 3002, 3007, 3012, 2802, 
    2808, 2388, 2391
  ) 
  AND pfv.lang_code = 'en'

Query time 0.00140

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "26.28"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "pfv",
          "access_type": "range",
          "possible_keys": [
            "PRIMARY",
            "fl",
            "variant_id",
            "lang_code",
            "product_id",
            "fpl"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "feature_id",
            "product_id"
          ],
          "key_length": "6",
          "rows_examined_per_scan": 22,
          "rows_produced_per_join": 12,
          "filtered": "56.37",
          "using_index": true,
          "cost_info": {
            "read_cost": "8.17",
            "eval_cost": "2.48",
            "prefix_cost": "10.65",
            "data_read_per_join": "9K"
          },
          "used_columns": [
            "feature_id",
            "product_id",
            "variant_id",
            "lang_code"
          ],
          "attached_condition": "((`portal`.`pfv`.`feature_id` = 73) and (`portal`.`pfv`.`product_id` in (2988,2992,2997,3002,3007,3012,2802,2808,2388,2391)) and (`portal`.`pfv`.`lang_code` = 'en'))"
        }
      },
      {
        "table": {
          "table_name": "fv",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY",
            "feature_id"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "variant_id"
          ],
          "key_length": "3",
          "ref": [
            "portal.pfv.variant_id"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 0,
          "filtered": "5.00",
          "cost_info": {
            "read_cost": "12.40",
            "eval_cost": "0.12",
            "prefix_cost": "25.53",
            "data_read_per_join": "724"
          },
          "used_columns": [
            "variant_id",
            "feature_id",
            "position"
          ],
          "attached_condition": "(`portal`.`fv`.`feature_id` = 73)"
        }
      },
      {
        "table": {
          "table_name": "fvd",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "variant_id",
            "lang_code"
          ],
          "key_length": "9",
          "ref": [
            "portal.pfv.variant_id",
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 0,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "0.62",
            "eval_cost": "0.12",
            "prefix_cost": "26.28",
            "data_read_per_join": "1K"
          },
          "used_columns": [
            "variant_id",
            "variant",
            "lang_code"
          ]
        }
      }
    ]
  }
}

Result

feature_id product_id variant_id position variant
73 2388 9803 0 L
73 2391 9803 0 L
73 2802 9801 0 S
73 2808 9801 0 S
73 2988 9802 0 M
73 2992 9801 0 S
73 2997 9801 0 S
73 3002 9801 0 S
73 3007 9801 0 S
73 3012 9801 0 S