SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '89ecb30d6583ff297f8d915542f420e258114fbfdcb6444de93463739a71263a' 
  AND token = 'Uste/fykLepR9tf6QvxwD9F4zCLIHHZv9OpHoYjPjz0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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