SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c0cc994639eb43730f45f0f147c7a5dce82956646c83b09b727de70604be43e' 
  AND token = 'qgGNQVYbASQHkhqlZ363MVkIHfUqOUZV5n8jyjbUWPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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