SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57da8c974fc4573bcaba12043b303f98d23109c416bb1e465afacc453fff41c8' 
  AND token = 'a43zsWBjB9NZxR3jdb/o/HXumJSlRD0QTHEM4Titbao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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