SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dad105e9f051c349bde7bbb8abb18dff83fca52a2439f4d4951649b7748c4159' 
  AND token = 'bTiTGJWKplWl3QGSxwfmf+yQcD3LTkwsgOoxvMrkaIo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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