SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8b85450c4da997cce6b18cb33fdf7c252705bf5713e602fdebdabb9698beec28' 
  AND token = 'BQLu0/zFHT1BWWttwTrU6qFPCSVWRPSsojV50j6NItY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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