SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = 'a09a9e2606837f90ab12fde64f9025b6a251dda2e4e305396dc16a315aec8958' 
  AND token = 'ht3ktF9UrwQc3yqfvYL0RvaaKOWeEirQqdN8hUaabXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00885

JSON explain

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