Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'e0c05c66a656fc01f2d3bafbd135a5955da70b9271c992d54b984f7a27bc1af9' 
  AND token = 'XiTQ1hghrglinswlqYQafp3NDbid73aylfXHsMx3u+Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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