SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '481b36e9a831efd186699e0fcdfed8f4026719aadd3a68b01ca8227634fa017a' 
  AND token = '9gOF8ZjpRmTfFz4N3W/VLk6hlZO+LXWJ5ln3WvTe8qU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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