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SELECT 
  * 
FROM 
  cscart_bm_blocks_content 
WHERE 
  object_id = 554430

Query time 0.14793

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_bm_blocks_content",
      "access_type": "ALL",
      "rows": 229724,
      "filtered": 100,
      "attached_condition": "cscart_bm_blocks_content.object_id = 554430"
    }
  }
}

Result

snapping_id	object_id	object_type	block_id	lang_code	content
0	554430	products	17	en	a:1:{s:7:"content";s:0:"";}