SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd366d391f5ed630bc957276073f66c717976939716693c53d712dadb15eb363b' 
  AND token = 'Fpa86NiagQWHngS6VqQ+qsxUYUyLkaJBvgA8cFf3H1M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}