SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a26c351e0c231bc639d7d35dbba69207609805add74cf715a3d0e56ab9f809f' 
  AND token = 'wU3Jn6IMTuXwJpdQA6JgE1dn5NPsbg+P3MGkd2EnKhw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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