SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b859dce8236ebe8a9af85bc60ce62553f55273f33e55cd435c49851bef86c93' 
  AND token = 'zDnpiEN1s2cspP5XhGMaXM0BESMrfqq7mORsNjrxxcY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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