SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '263e8c0d4122a27da0171b7915a0ee3f4f22fe259b8f96ed1e8f8cb9e6ddf658' 
  AND token = '5BjRyGoMCVgGD/+i45KSUVq98ld+BMQg50Ksi9OPkBI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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