SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '940a863570bb02b3a36a6699173e956caf164bbf1a55979c9552b29da95493d2' 
  AND token = 'qTjkZAwdbeyXRNsiGxx49eHvGNcUyEwro3ew5e5ltVg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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