SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '659d944ef40dd135ec95ddb779ad521dcd1881bf85b093d2bfede951ec1a9adf' 
  AND token = 'Ha+PVGUPs2YWRX1NGSwvMnnA4iTVFpQfqR4+NfaycgM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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