SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '61d1b6f2be7a8440cbc3554b6c1d2d151b1b2f99760795fff220aeb315fa4f3d' 
  AND token = 'YwXuyd9qFBWgZQixdBx6Y5c57sHdZvHUpGspON7nVz4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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