SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '79d8969dc376db6b3fde1326719de4d2c630611def69c43d53e31b1ad4cc427c' 
  AND token = 's5dyJVfSeyFax6bfrsJGZVCGLOUS44ctpvFKV5G9Qq0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00853

JSON explain

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