SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'afac92b0fb13a55a0472bd1c08567f3d222e8f2dcea708b6f72b7f062b707fed' 
  AND token = 'ZCT2SAJuJTzESNhEf+/ZbHfFiYp2NjB4AqY623D1ecw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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