SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '480124b027b02f31a379438dce9129da748a8b5ae7d832905f77d482799f58c1' 
  AND token = 'uPQ7Ikg4wWE5L1dlhLxHeuG/feOxG1EuT8aRtbmLxds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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