SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05a055d8fc34bdc96a1148463e95f83740d1eb2d4351c46560e0ebae7ed40624' 
  AND token = 'wuLVfkJfY+PQEDDEVKXInnJizvjnrMm72OX5smxpki8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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