SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '548722a2b4a539f29288d8053afdfe93ed1fafe5ec6d4beaba9c747bf5aed4bc' 
  AND token = 'YALHcEnic2SdAOsDxmOJBZ4UzfA5gyVJpyXqaMo+JYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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