SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7f67bc40c07f7d37af7f13b563f006c940ef8d332f159b1e55e52335d08c122' 
  AND token = 'LG5JsAzNYkJPiwM6GfxdaSaEmojwV7ond+BnYOQ3NlQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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