SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0e4b08542bf01f1810f21a4c202e5e79d183a57bab1785b915d6b7ec5d7fcd0' 
  AND token = 'O7b7y6JiDsIf0TgOxxaSVNyxZFoEynYOPrk6T+9NTbE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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