SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '3cebdd4992df6e15c355f0925ccc5f8e8ac5c5a35745a757de6a2df645a367bd' 
  AND token = '4aguJmsZ65nfCmFuF0K+JV+4WpOc731ZFwpz7Nff27o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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