SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17933841805506691c1ca752846db9fba79dd5539c316a87a262dbd6ed2f80e8' 
  AND token = 'kUVa2KT5IEl7jfXGyVu+EjdhjdiKD6PE91arUPrFxfI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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