SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0b3161728a61be9eba8e0a5386dcfdf08fd06a6e183edcc7e3145dd45a49f13' 
  AND token = '9cs3hDhk9Lp6td8IStscoJVq0hCX4zsVg6vG/1ZyBTc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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