SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9b749024bab718e83b9d4f7397d2289cc02beb745c70900d9346b3655aed0ac0' 
  AND token = 'TSyt1R5CWOzVHKudO+oAygrjD9VtcGQZixCX5AZOkKM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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