SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '4d708d73034df21d139a1b75d2d15038af3f4f2167c152dc3776380387b382d3' 
  AND token = 'SVswNhcQtyJ1NsDsQmzflo2wqf9hDrFxd8rEz4LZHaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00769

JSON explain

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