SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '873cfcc0154c93f4aacbffa4d6d4fc44cdc21039b16f9778a7aad14b750c160a' 
  AND token = 'Z9TFf/sooLbHjbErDiQaXkLRfCfLpXCd7aceETlG7UQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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