SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41b0ffbdf63694ce15db706c545a5bba08e63647ee2301771c71509b167fc53e' 
  AND token = 'pXt/U+fF+K+pfUUAllXX+mArEpKRsXSqVAokC+TfEwE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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