SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec7175f5aa93671c2e24c0c573e886211887b154f28b37d26620197f73d06305' 
  AND token = 'sdl2JOsvkMpME7AGk4csJboLYf7Yl75bXt3lsEjKwBI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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