SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8eb25fffe33f02d8134a6872d9827a8abac26e01b533aedd2ad6cc8b706c900b' 
  AND token = 'TRi8TaHplM/ojpueWfyQARUZiaUhkvrWYA9DOIphnKM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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