SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '70984348406b8f213d210becfa041122e6c21aa10e9e1c5d477f4f61bdb8c989' 
  AND token = 'PJfTQsdPO7J0yPpb4bXD5uTuD5Lfs072p5Z4DJySNmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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