SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c63930d0c3e32edc5337c8b1ac28c96a4f2a09b31b046a60bcf8b1128874034' 
  AND token = 'xJxwudF8EGfUjwMDvpOw21GUPzqrugAe6UWGjVaW3VE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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