SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b036171b6ba28e11fec03800bc54ccaebefaacdd90f98acb9d7de00b39c38a44' 
  AND token = 'bqyTvrJnAmaKrHUTgCLhSHs2v2AxonHtqJisPD22Yok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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