SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe27d86bee1fe0b8e2a3e4c7809511fb1de083a40396b48dca3e07c16b94f5ca' 
  AND token = 'LPn4GF1zggqz8Fm/zrxiRTnh3U7Q8gCFEkn5ul9fdjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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