SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '299438566c03ac73dde7a4f744503bd02553f4563f5f7242e9074cb769852eec' 
  AND token = 'sQqLmV0OmwxV0rR5VKhEbnDGGjhVuinGEhmzh7vERFk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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