SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '61e07fdbe2ef45aa1e4e3b3ff158017ee60f8e21402c64c04076b46e16f8f83d' 
  AND token = 'd6QdjS3kNBXB7K/lpLVJ5riw+ZqiHu0MkrsORs1E05s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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