SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '13c80c7b8ec0ce10a394d7b2b178beecbee7a65422fdec04f4fbe31931bb7281' 
  AND token = 'xYVXJkLMGBLEfXIMQKTfNSWMT6N6sLXph6D3ZV84OnU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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