SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93768bfdf35b54690abfe1f2b011288c80be522e32caad643c11eefef47f4227' 
  AND token = 'Q/8Yn+5OPfiQGbgU6B/7YGgjWd1o08WIuukgucO7+gA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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