SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bf7ad07ffe2da6c2a0bce875d636a44011bd04da0cbaf9eb90a492d92e4e7e5' 
  AND token = 'K0t9gPczfQUX8omWQGbcVtVZm6ZVkIyAkYK7plEECwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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