SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5601baf0cad823d5718febd864812cf5e87e5f5ea11f78f25dda40b81fd3ce62' 
  AND token = '37iTRwMDtmafmuhzJBKf1RDBEXJhjEGWPM4qDXG82SU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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