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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9f877db2e73d55ac93098e8fcbe2ad79ff0dadd61cf45252b26cdf8d17b6b00' 
  AND token = 'W4P0MbM3RwFfHb/ilGYh4UIvBtAKTdLvuB5SuOo6Vu4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}