SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88f9eb7b11d490ce9173745c048773421d8bb8bc7f1f7fec0ca6f302d18d4d10' 
  AND token = 'jlnXI3PZaoNnxY9elJbOB7CPf5IMIA5q1YuhugV7tQY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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