SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a988a5057bf8f26f488802b98f83430c8815827afce53782ac4bedd7f813a8d' 
  AND token = 'kvpWQZMGs8mqa0cEqyNukFcI+KqAsnJiRGqtFO9NlhM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}