SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b768a5ee80dcdb556093bfbe5a076d86c33a4a8fb257013d475c309dd1c41799' 
  AND token = 'ILdmZeuZoiZgtVuOG+NS/e1naqf0A8MsNb65CQbQqlU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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