SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36f7a241de6ec8f5d7f15035aa705305a6f913f570901839c6a4329e8c289f04' 
  AND token = 'C9Z4+wMYhbEmPzQal3N81LL77p7oNgfDbVkseXd1EOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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