SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = 'c7a50d89421261468c7e7d55946d031ac090bd8c2dcb7c4d2bdb4a8a333949be' 
  AND token = 'JjMljzHAtziZKk7Kf5DgoZDkGaBFsa6ZIfVRALVwlo0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00890

JSON explain

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