SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eeb8dbf43f3cef73922daca44e542f1350781d50c78cd1fc53e11ced36c9bf46' 
  AND token = 'qinK+5Irj3uXmFilwmTcOBfYv7O+HDhdzNheqLi9shg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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