SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b28e0eeaa61d0d0ce389c281abd437bf908d950f32cdea37162d828ecd1bd8f' 
  AND token = 'IOVsfmuQ9gP8+X2lO1STzb0eC0vHA8bvz4t4S8r9whw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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