SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42c56853401bd7fd2121dc576605f985fb3da3050552aab75e98d20007bb23e8' 
  AND token = 'eebVYZayQFFBYuGJvnUJ9B/gnwjgaNS8qB61vM3T6OE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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