SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c52b3516960d294d9a36158030bd9f18d065251ba9ccc0f7b422df11450e3a3' 
  AND token = 'BJLU8OzIfuPkmRIb69JzG/duw6S3nWWFyIyBaDGWXjk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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