Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'b3263f80d1fbfae024a814356b3999f9f54a55ee347d715e935eebc370d215d0' 
  AND token = 'qrNKhPTn89CBlkl1oArMBdbc7qALl4RQVXVKzp0ghzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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