SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '813d7ede2b7d3b6dd6d01c4ead652efd3185894801c304fcce99462a5f44e9d4' 
  AND token = '+JiCC6ihJnU8PlC9CnXZYc+0cGb6Xm2dixRF+kPEEYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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