Sandbox

SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '76cb598f67dfdb0412461a97d555ba47e97341c592a3b920ac1d2a72239852aa' 
  AND token = 'UKfmIibPWfRLMilkS9mgM9R5tSq5jWT2xXEAf1rvlBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00777

JSON explain

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