SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad83505a4cc36f913a31358f09470d5409f2c3b250118badb4669b5862ddaff8' 
  AND token = 'JX7zlBYspXljBH7k/qvHgO39rVt8pl3Wke0IZjQHKg8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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