SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '724dd64b73825c53582b4551e00088bc3b757faf07a4fb96c11dccfc194d7bd1' 
  AND token = 'IW/NqdAArXKUxK8QGx9j07YsUESjGET5RMdKU8JLZ/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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