SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3397113ebe8f8d2138f2ae43a2e1fb3c8dbb2de02f5a8235be01c505624ea83d' 
  AND token = 'HOIyebr14DTX6ckfKp5RvPH4S4eXlfyWPa/a23Cw78o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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