SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13e4bd69ad032f5af31ee2361d1266b67014ca6ac3045057f2afefc2bf05f80e' 
  AND token = 'Y6pRBMB/+79AfUBod6T/6klvPiSXImHOLiULxDinbpw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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