SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '72fa64c97bc142a7ef478cd92e648ec29f5dc8264e3ccb563232c9707040e93c' 
  AND token = 'nXhmCFgeGZ5l9bocrqmI9jtUZrR65OGSQ4fPiVyLt0E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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