SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd115fe53188d4483dfffec6a197b20eab567d8254eedfef502b6627ed528633d' 
  AND token = 'CFdyTfYuDm769RizSTdeaVqueiga7uFviUP8ECQKXGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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