SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7dcb013f3bbf495aa8abef8194cc3da588262abeddc3b77076ec1a49fc79c5b' 
  AND token = 'evbH5ObJiQTWOpi0UVktF0dBblowslXQsWV8JHyJMpE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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