SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03b15289195cc053bb3f2ef5cd7805f83898ca5e221738d5ebc63fa76732b165' 
  AND token = 'moCBHDxasfLtLBVhY0De97vIpzomYBuyam6WI4zqirs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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