SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a805471d508fec3058964230bebba49266f9f16f09f937a45670e3f2effdd43' 
  AND token = 'QfDoBREm2jD3sSJZ11MwRwkKBqh8pPlAFRobtrm330E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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