SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'af86e79d542348ee100fdc7761c86ce34dad6e51df740227a83b32ebf5e6b9f3' 
  AND token = 'LKas8SgxJRdUnWa8qwBDNXo5wKOI9DDNZ0oz4ay0nOo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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