SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '82611c40857327616458ac5f6dbff84a2b6ad24cb30679dfcae4b5fa86abbbd8' 
  AND token = '6XB7/KbLnq5pxeVcY+br74+UhDD5CFuLc3q8i+VB/Jw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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