SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '382b9ceb285b1754dab138c80e68a2db722dce4106966e2e07853d6350384241' 
  AND token = 'TDW+dG5uSlkJhWfOl6GZLbnUToNkWBQHDoijjwQ9V8Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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