SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26d2fb0aadb50d56c6e483c8fe56192533a1ac95192934caee4093ca1832fcb6' 
  AND token = 'MFx/uT6DXg5olAXbsPLDw7RIu36D16/lkrVB7SKFf+c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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