SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '326a836778fd2902499ea3f9af58e0ebfc32a5cafdb9e0db569f36270d753e88' 
  AND token = 'TGRAJVu4JH/HI7AjS9XGksSgdFfUzXZAJynZBDaYDVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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