SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '7ce6a67dd96b9d1fb7dc9a6e055d84a8d70c3380d7ab8d17f059366a9255e0af' 
  AND token = 'MGOOIGPr2ZAcysdnqA97cCj53+f3KOV/k1r4nwEydIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00804

JSON explain

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