SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9169fdf066389c906c6760df7ac4d52c9329967386b7390f85ef52135947be4e' 
  AND token = 'zh1KyjO992gowlElIxeVJuldHuPJQVlBbIYZqajqh1s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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