SELECT 
  `hash` 
FROM 
  `hash_filters` 
WHERE 
  `link` = 'alfa-lizing'

Query time 0.03078

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "11.85"
    },
    "table": {
      "table_name": "hash_filters",
      "access_type": "ALL",
      "rows_examined_per_scan": 106,
      "rows_produced_per_join": 10,
      "filtered": "10.00",
      "cost_info": {
        "read_cost": "10.79",
        "eval_cost": "1.06",
        "prefix_cost": "11.85",
        "data_read_per_join": "60K"
      },
      "used_columns": [
        "hash",
        "link"
      ],
      "attached_condition": "(`dev2`.`hash_filters`.`link` = 'alfa-lizing')"
    }
  }
}