SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fdf7cfabfa4f308cb0c92e7ea0dd143515cf430e1e5d5557d45a7e9e32b65cb4' 
  AND token = 'd4/zMYae0+1Z3mCXjLG8ITcY84jFYmKqP7b7LY2GZJI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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