SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7092f785350d9c5408676ece8bb0f71fb91a4460dcbe1e132188cdf64810c13' 
  AND token = 'IVDd9jqay48gVdtD+iM8ONnZciunjYstBzMeGMnNNII=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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