SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = 'cdf90e9683eca4bc2cc57b5eb5ad9e27d781bff8196499a79749caa5bb800701' 
  AND token = 'vVaa/WMWPQpSi4V51bYQF58QFVuBQaYwUxPMnNW6XoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00760

JSON explain

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