SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ffdce4e002865653e20daa28f9faed04d4920db73f426583b140d614c5d77ac' 
  AND token = 'vhHwJmzAqL9+DPgMu3j9pbvIc/Ha9gFORK8myxG2KG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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