SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c62411ec0d48b9ba1bd9609efcd4951a4f5cdb0ee6f10157063a12ed0cc9a9eb' 
  AND token = 'prBlsre0svwrQgH4HLMzw8QTp6mdHaPVe3X4g9nQEvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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