SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a96562e86aaf1a8529102b091a05e4986102b19de4e847d4bc35249b6049a82' 
  AND token = 'C4ppwbrDp5UDwLK4EPQW61gS5WwJbqPrVc/4FiusCl4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}