SELECT 
  n.sf_id, 
  n.features_hash, 
  n.show_in_breadcrumbs, 
  nd.product_breadcrumb 
FROM 
  cscart_ab__sf_names as n 
  INNER JOIN cscart_ab__sf_name_descriptions as nd ON (
    nd.sf_id = n.sf_id 
    AND nd.lang_code = 'en'
  ) 
WHERE 
  (
    (
      LENGTH(n.features_hash)= 6 
      AND LOCATE('1-1892', n.features_hash) > 0
    ) 
    OR (
      LENGTH(n.features_hash)= 7 
      AND LOCATE('29-1870', n.features_hash) > 0
    ) 
    OR (
      LENGTH(n.features_hash)= 6 
      AND LOCATE('65-135', n.features_hash) > 0
    ) 
    OR (
      LENGTH(n.features_hash)= 5 
      AND LOCATE('65-50', n.features_hash) > 0
    )
  ) 
  AND n.category_id = 510 
  AND n.fixed in ('F', 'U') 
  AND n.company_id = 1

Query time 0.00061

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "n",
          "access_type": "range",
          "possible_keys": ["PRIMARY", "fixed_category_hash"],
          "key": "fixed_category_hash",
          "key_length": "7",
          "used_key_parts": ["fixed", "category_id"],
          "rows": 61,
          "filtered": 100,
          "index_condition": "n.category_id = 510 and (octet_length(n.features_hash) = 6 and locate('1-1892',n.features_hash) > 0 or octet_length(n.features_hash) = 7 and locate('29-1870',n.features_hash) > 0 or octet_length(n.features_hash) = 6 and locate('65-135',n.features_hash) > 0 or octet_length(n.features_hash) = 5 and locate('65-50',n.features_hash) > 0) and n.`fixed` in ('F','U')",
          "attached_condition": "n.company_id = 1"
        }
      },
      {
        "table": {
          "table_name": "nd",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "10",
          "used_key_parts": ["sf_id", "lang_code"],
          "ref": ["lillyshop_lillyshop.n.sf_id", "const"],
          "rows": 1,
          "filtered": 100,
          "attached_condition": "nd.lang_code = 'en'"
        }
      }
    ]
  }
}