SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '469e259c5374ebe7581bc757c0c75327043dabc8b47828e342a4c283379a09cd' 
  AND token = 'j0urZrj5gQ9RgLgjq+aIZgmZKUWT7gWsYfJs9LYMi7s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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