SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9540efd9153abf4c48689b56907e3864d215fc045ba6fbbdf7f891b2657ce0e0' 
  AND token = '5OIDCZHdq8dRL3zc3hqvjBUxm9TxnJPIWUnOJhem41Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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