SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6423ae5523ac33affa1e227507305fc5607b58422164243254a8594a9a64cf5' 
  AND token = 'cPfna40TlEuHSmLvGBp5uK4EWTZa4eDpAkR1UIBzrKs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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