SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '14910f55d1ec2aaabda317ccd124249efdf7a0c21e4c573588e311bf8e9b8ec8' 
  AND token = 'qKUKPGLZitxavk0ELVDXxNHKe2bSUImfBhiDERSi+UI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00797

JSON explain

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