SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c484bd2c0d0f0d8d55bfc04322d0d000c513676abceea516db400c4d806c9aea' 
  AND token = 'mNc4JhvkWibu1nqXtCyUTL5CmYYGUMjETOfvI7Z4iUI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}