SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ce37ae0ecdbf140e1ae438ee7c83a1492ae65914b4b316464edabe41a9c94dc7' 
  AND token = '+TIbTvnAet0JpHFRNO81SW7U+4OJt4RIWviIbWsU1zg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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