SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '86f36a30d81c15d7db0782d775563ef29e074fb09614d8c04c0f8274942a5732' 
  AND token = 'E1XuOujIUi4GjF+f6TpIq9DMka/xgj9tltQY0pNU0Gg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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