SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '38edeede01cfa6556e237489f1128ed9f80fde36d2909fcd4317d98bca5dff52' 
  AND token = 'qePH4vT9VsM/9HusANO7ZKXRmKJ636vYH95/AvChWQU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00989

JSON explain

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