SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '081333d06024c5a0c782d62a050ff294b7b9ea7330f76e311d8046db7886b6c4' 
  AND token = 'rgaVxqBiHMZRwsOC81fIbKLvABzNF71jH8e9G9jboRU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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