SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'b6d7b9082f4d9356c481e838f28e4d9c5b8ae04f37eca027665dd97500d1a079' 
  AND token = 'CBPv8Xoj2RGMvcvD3DwoK+eP93jZ03wLtzjNsHfLjLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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