SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '7be2c333066412d95606b337070bce4f15305080ad1ee051e8f6eb17aac315a0' 
  AND token = 'u8itsOMsMqxn4JBKD6No716rfN7jKExGV1cwuxfAdPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00752

JSON explain

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