SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '9eae98609e0275707b72b6fc5a8d595151153da9ad47a582834d6387f2d519cd' 
  AND token = 'jxBDhK1++xFM4GOSYAtkuXTqx01L48ZhzsHbp0Gl2ZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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