SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd58a1b034af9f2b037c32c9ba1d533dd6fc25980ef189812c26d617ab18dbd6e' 
  AND token = 'i4tlrSVgLub7S7fvXd5PWGmHH3iJM5ix16HUwsfAuIQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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