SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '857c71b8383478c884fa5931f9024cb1d8898968831a5d13b3ad803811df5e8a' 
  AND token = 'py17VDAT3qXSx8XvK5TtvMUdhV/HX4l17tlCSw0nRbo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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