SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecb369a25c632308c8c4915a1816f676fd9d48c0c8585586d1b07f3bc43f2284' 
  AND token = 'wPIhYigzlLGEh1GmrOAwEIPeW0Zzzo074+gYxxP+jNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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