SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96780832eaf29dd2d641454594737460e3d55aaf60a087064d316cf9fde3bce5' 
  AND token = 'oY7875uv4yQPz7R9Qr+zlUeGdVsoGfQvYkCZcupI7h8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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