SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7d23fc5e265091fc2a8148017e0b9b862b321947ebe4d318993b1f2a6538b8e' 
  AND token = 'qTwOT5qjVns/mRl6dvwcrWygvxH/FOuAzmp3roeKekI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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