SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd976a30bc1e5844bc7f93034b6bd6ab22216a8217a82a1e8dda1417f7f9c5286' 
  AND token = 'Qu6xPc3mkTv/U8Xa/4/dUMSo/jOHFwB7pYO1Vb95YIk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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