SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83bf2638325e8633166c6bbffde758064738ba60cb7fc90b8147e67961bf00ff' 
  AND token = 'TL95UMxenXFmfK4u8EKVfwRUteMF430l6swFRWiuCdU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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