SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5595a6dd1a81f47fd898aba4d8061d39e5c5eb18c420b2ad3da0d073f90258d2' 
  AND token = 'chzS0V/VKb2Mw5MxdFnA30XskZuD2C6yfL71tlCmnD0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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