SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '027b4ec764dd74d9a68fc8f43350c89c2a1de146197285851c46f4c005b6984c' 
  AND token = 'P3qJpDJ4l25EMaZ/zH7xUwtKaS5xT5jTB7zw+aVLeIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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