SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'cc9f3574491b5f1af41da0ed4536e42d60352f8a791454af5f51b9809f502063' 
  AND token = '0O4FeZPodpfbLyQO0XwRb1XOlYVBxQ7S9cjwlUqDgNg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}