SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ffb906ea6378f7584d119579867c76f2bf51b7914464c43d404deae6dfb0472' 
  AND token = 'tNnWfwlL42qhbyLNGm16G7XcHn6mi3dWYWGbvehcbaQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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