SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'afe3b14dabb150cf5a94e4ed753e2f7bdfc33e8cbaa5074c54a3a01519faa668' 
  AND token = 'ZXt0vQ3SnMNJKAKV+pcloh/SdGP8+S+VV6svo7XyYwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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