SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14173eb85804f4b041980d5b3370a108dedb2b5f364f9264a95d5e9907188837' 
  AND token = '0THLfAmbCGnQB45EiWtogWoMFiOOB2IrLnYloO10yjU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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