SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '932c3b8140f2b17d52dfc675ef8ff791d1da8a86370173c2aabfdbadb0a741d0' 
  AND token = 'n9pe6E/NEZn0RVmqrLguZhyUTZ0/6KRjQqjvn8CJmW0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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