SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88d158f14e7b6b828ada6d15cfd560b744efd7aa177168e2b41d9040baba80d7' 
  AND token = 'nyXkW3zfov9qaPPpET3KF0uRdq3EC+gWj4oL7Dyrp1I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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