SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bffe806b13710c04485787669b860baec370a0bbd912b4eee9840b7520f169e8' 
  AND token = '4IFc6JaJGRwXHb50kdR60JKUAU4guLp8SxRqAp+WtJ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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