SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fdb07851ba5710d54dd547bd7444b2739545b92df025dee5c9de534304bcc68f' 
  AND token = 'tUAmuF25r9uifC2J/tgveEQ369804qABxqCC1o1lGmQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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