SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24939801a645ce0f481a3a73121edd24e42c01a67a9df09258b05e652a71f5fc' 
  AND token = 'SFimyL9/hwuGjVWj9F/iuLRYjl8gfVU4J9dl+cD6/5A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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