SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2797425f743563cb76a5695270d9f1e4ee8398086547f1d4c32072e9fb14a10f' 
  AND token = 'QYxMT9QPvhwmkj9qOGqTxzejPzT5spvAezTJ4ML2ZNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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