SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85d6107fe4ac962dce20201db0252f44ac24195e99b939a4827307fe0a4d2bae' 
  AND token = 'nc20QV7IiI8Wns8RZwsCgaVm6wkB8lppo2lUApe/rzA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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