SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0b5360318388a158b0660fea752e247f57d7807ddebe71711d4100c5cd798d8' 
  AND token = 'yY3iLUEa1BBSE0JUNko8cFm3eyzW6wj4rOyqy8FoJE4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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