SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3233e3649013cfe36a3825b37d0383f9d747fb9dcefb942bd53aa5ebaf69dae7' 
  AND token = 'RYqQihdeaEtXndHNN5mtEYZKQNujF0l7GHaFZKGHojQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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