SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad4042b83879372401bfc634215d7f6980911b5f7101075e7e24fb53b5237927' 
  AND token = 'rtFNIRwnynNG/WDJl1BLDmEwtoG/0aD/nnwdSYs3NmM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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