SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '4a5e19ab78c0f3f262b42fe53d7edcf5eebd60878708113d0a781f16093ff9fc' 
  AND token = 'N6hWMAVjP58glmZqBzgGTJqks2v8M2UbNQu3EMSZtY4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00966

JSON explain

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