SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2afa868a651d30159c198a70df759a3cfbbef4b4e5fad183498d1ffe235f8918' 
  AND token = 'bmKxR1TmL0Xl4mjmGMqo5iwb4NBo7V7det5T2OYMnP4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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