SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '387acf02bee996b49f3378360442c59605736cca6a88cca217cd447b69c70392' 
  AND token = 'OYU3eaVEwPyUQzf6J3o5Huc9VJrwkMlQnUlFFwP7DiA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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