SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '969a86d8186f3b6552e67567a287d3864105200b282a1847ac7f8c039c4214c4' 
  AND token = 'gwT5tJeQd+dErhnWR7tGypS6d+4XiOzYvJaLEgY9Bfg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00944

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}