SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59afe4b8f23f68ad25ee625eabacf43afeda9f3977f0d1b9771e9868d68afbd8' 
  AND token = 'nHpYUrgluRhi9Wbrh9N43MpL/EfZWvhMfPDRnRrRyzc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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