SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '232d950a64c7db3e11909118c898f1bbee568d126fe1dac4504fe987bf786977' 
  AND token = 'w6HD4I39HedpBj/8LAbNBXjAJtf9t0AVns3LVKxXuJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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