SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3501ea7516c587432777664eb97e654f2b367d7c5b1c40cae9fa9c13cc42cbb8' 
  AND token = 'XSSXAcZAxbfNPQ/B4sRnQqAwlRU/Xwk5Ymm6KvY66UA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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