SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '585efa16428f33e21fd2f9b6b1459cd6e12ab834693fc5773d248b1a3f23bc9c' 
  AND token = '/6vBfNoxy56ysyqeRwhGrL/5sirwZqIU2sY6sC/SsYM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00800

JSON explain

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