SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09b5db1f04ce00d7fa13692053c49fe4c34abe1cb55dfcdda9cfb13efbeffe83' 
  AND token = 'qla9SOIcaFXIiZH+fDMyDzRVUOCLUWRYEAZzT0L0pCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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