SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '035e071b8201ff666472bab031e73557f2fa44d81c6e3276591741ad7b570078' 
  AND token = 'xoYK06yPvN1z/8KvrCKWQOHyTZ3mf0WsP/87JVrstSI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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